Server Quality Checklist

Tool Scores

• pixelart_draw_rectC
  2.9/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations provide idempotentHint=true and destructiveHint=false, but the description adds no extra behavioral context (e.g., overwriting behavior, return format details besides 'confirmation string').

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Two short paragraphs with clear sections for arguments and returns. Efficient but could benefit from bullet points or more structure.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Despite having an output schema and sibling tools, the description omits coordinate system details, prerequisites, and typical use cases. Not complete for a parameter-heavy tool.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  With 0% schema description coverage, the text lists parameters but fails to explain coordinate semantics (e.g., x0,y0 vs x1,y1 meaning) or color format details beyond what's in the schema. The fill parameter is explained in schema, not description.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the action (draw), resource (a rectangle on a canvas), and variants (outline or filled). It distinguishes from sibling tools like draw_line, draw_circle.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance on when to use this tool versus alternatives (e.g., set_pixel for single pixels, draw_line for lines). No mention of prerequisites like canvas existence or coordinate system.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_delete_canvasB
  3.2/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already provide destructiveHint=true and idempotentHint=true. The description adds only that removal is 'from memory', which is consistent but does not significantly extend beyond annotations. No contradictions.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is very short (3 lines) and front-loaded with the main purpose. Every sentence is necessary, though the args/return lines could be integrated. Appropriate for a simple deletion tool.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool's simplicity, annotations, and output schema, the description is adequate but minimal. It covers the core action and when to use, but lacks detail on parameter semantics and return value specifics.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0%, so the description must compensate. It mentions 'canvas_id' but provides no explanation of its meaning, format, or constraints. This adds minimal value beyond the parameter name.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose4/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the action 'Remove a canvas from memory' with a specific resource (canvas) and verb (delete). However, it does not differentiate from sibling tools like pixelart_clear_canvas, which might be confused with deletion.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The phrase 'once it's no longer needed' provides implicit guidance on when to use the tool, but no explicit contrast with alternatives or conditions for not using it. The tool is straightforward, but guidelines are minimal.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_flood_fillB
  3.2/5.0
  Behavior2/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations provide readOnlyHint=false, destructiveHint=false, idempotentHint=true, but the description adds little beyond returning a confirmation string. It does not mention that the fill replaces the color of the starting pixel and its connected same-colored neighbors, nor any side effects or requirements.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is short and front-loaded with the main action. The 'Args:' line is somewhat redundant with the schema but not harmful. Every sentence earns its place, though it could be slightly more concise.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness2/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the complexity of a flood fill operation and the presence of sibling tools, the description is incomplete. It does not explain that the fill targets the contiguous same-colored region, nor does it mention constraints like canvas existence or coordinate validity. The output schema (confirmation string) is not leveraged for clarity.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The description lists parameters (canvas_id, x, y, color) without adding meaning beyond the schema. The schema has a description for color, but the tool description does not explain coordinate bounds, canvas_id context, or format details. With 0% schema description coverage, the description fails to compensate.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states 'Flood-fill the contiguous region containing (x, y) with a color.' This specifies the action (flood fill), resource (pixel art canvas region), and distinguishes from sibling tools like set_pixel or draw_line which operate on single pixels or lines.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies usage for filling a contiguous area of the same color, but provides no explicit guidance on when to use this tool versus alternatives like draw_rect or set_pixel, nor any exclusions or prerequisites.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_create_tilesetB
  3.3/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  The description states that the tool creates a new tileset and returns a JSON confirmation, which aligns with the annotations (readOnlyHint=false, destructiveHint=false). However, it does not disclose what happens if a tileset with the same ID already exists, nor does it mention any side effects beyond creation.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise (3-4 lines) and front-loaded with the purpose. It avoids unnecessary fluff. However, the use of a docstring style with 'Args:' and 'Returns:' is slightly verbose but acceptable.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The description covers the basic purpose and return format, and the output schema exists to detail the return structure. However, it lacks context about default values (e.g., ppu defaults to 16), constraints, or how this tool fits into the broader workflow with sibling tools like pixelart_suggest_tile_size.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  With 0% schema description coverage, the description merely lists parameter names (tileset_id, tile_width, etc.) without explaining their meaning beyond the names. For example, 'ppu' is ambiguous (pixels per unit), and no defaults or constraints are mentioned. The description adds minimal value over the schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose: 'Create a blank tileset sheet (grid of equally-sized tile slots).' It distinguishes this creation tool from sibling tools like pixelart_set_tile or pixelart_export_tileset, which modify or export existing tilesets.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is provided on when to use this tool versus alternatives like pixelart_import_canvas or when not to use it. The description does not mention prerequisites or scenarios where another tool would be more appropriate.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_draw_lineB
  3.3/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already declare idempotentHint=true and destructiveHint=false. The description adds no extra behavioral context beyond stating the action, but it is consistent with annotations. No contradictions found.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is very short and front-loaded with the action statement. However, the 'Args' list could be formatted more clearly or include descriptions for each parameter.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The description covers the basic purpose and parameters, but lacks context about canvas coordinate system, bounds, or how the line is rendered. Given the tool's simplicity and sibling context, it is minimally adequate.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The description merely lists parameter names without adding meaning beyond the input schema. With 0% schema description coverage, the description should compensate, but it provides no explanation of coordinates or usage context.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool draws a straight line on a canvas between two points, using a specific verb and resource. It distinguishes itself from sibling tools like draw_rect, draw_circle, and set_pixel by focusing on lines.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description provides no guidance on when to use this tool versus alternatives, nor does it mention any prerequisites or conditions. It merely describes the action without usage context.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_set_tileB
  3.3/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations indicate readOnlyHint=false (modifies), destructiveHint=false, idempotentHint=true. The description confirms it places a canvas, which aligns with modifications. However, it does not disclose behavior on overwriting existing slots, empty canvas, or error conditions. No contradiction with annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise with a clear purpose line followed by an Args/Returns block. It avoids fluff but could benefit from slightly more structure (e.g., bullet points for args).

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given parameter count is 1 (a single params object) and an output schema exists (confirmation string), the description provides minimal context. It does not explain side effects, error handling, or relationship with other tileset tools. Adequate but not comprehensive.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0% (top-level param lacks description; nested params have descriptions but overall coverage is low). The description lists parameter names but adds no semantic value beyond the schema. For example, it does not explain the row-major indexing or what 'canvas_id' refers to in more detail.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the action ('Place a drawn canvas into a tileset slot') with a specific verb ('Place') and resource context (canvas into tileset slot). It distinguishes from sibling tools like pixelart_create_tileset (creation) and pixelart_export_tileset (export).

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance on when to use this tool versus alternatives. It does not mention prerequisites (e.g., need an existing tileset and canvas) or scenarios where this tool is appropriate. Sibling tools like pixelart_create_tileset or pixelart_delete_tileset exist but no comparison is given.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_clear_canvasB
  3.4/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already indicate destructiveHint=true and idempotentHint=true. The description adds that the background default is fully transparent and returns a confirmation string, but does not elaborate on side effects, permissions, or error conditions. It provides marginal value beyond annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is two sentences with a clear parameter list. It is efficient with no extraneous information, though the parameter list could be integrated more fluidly.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The description covers the basic operation but does not mention error handling (e.g., what happens if canvas_id does not exist) or any return details beyond a confirmation string. Given the tool's simplicity, it is minimally complete.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The input schema has description coverage at 0% (though background property has a description in schema). The tool description restates the parameters and default value but adds no new semantic detail beyond what the schema provides. A baseline score of 3 is appropriate given low coverage.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states 'Erase all drawing on a canvas back to a flat background color,' specifying the verb 'erase' and the resource 'canvas.' It distinguishes from sibling tools that perform more granular operations like setting pixels or drawing shapes.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description only lists arguments but does not provide explicit guidance on when to use this tool versus alternatives, such as pixelart_delete_canvas or pixelart_duplicate_canvas. It lacks context for when-not-to-use or prerequisites.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_extract_paletteA
  3.5/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already mark it as read-only and idempotent. The description adds the return format (JSON with colors), which is useful but does not go beyond the annotation safety profile.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is extremely concise: two sentences plus an Args/Returns list. Every element earns its place with no redundancy.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the output schema exists, the description adequately covers return format. It could mention prerequisites (canvas existence) but annotations sufficiently handle safety and read-only nature.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  With 0% schema description coverage, the description must explain parameters. It lists canvas_id and n_colors but provides no additional meaning beyond the argument names. The roles of parameters are implied but not clarified.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool extracts dominant colors from a canvas, with a specific verb 'Extract' and resource 'canvas'. It distinguishes from sibling tools like 'generate_palette' which creates a palette rather than reading from an existing canvas.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance is given on when to use this tool versus alternatives (e.g., pixelart_generate_palette). The description only mentions arguments but does not specify context or exclusions.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_get_canvas_previewA
  3.5/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already declare readOnlyHint=true, idempotentHint=true, and destructiveHint=false. The description adds behavioral context: the output is an upscaled PNG using nearest-neighbor interpolation, and the scale parameter aids visibility of small pixel art. It does not contradict annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is short and front-loaded, with a clear docstring format. Every sentence adds value, though the structure could be slightly more compact.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given no output schema, the description explains the return type (Image: PNG preview). It covers the scale parameter's role but lacks mention of error conditions (e.g., canvas not found) or size limits, which would improve completeness.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage is 0%, meaning the schema provides no explanations. The description lists the two parameters (canvas_id, scale) and clarifies scale as a nearest-neighbor upscale factor, but canvas_id remains unexplained. This adds some meaning but leaves a gap.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose: 'Return the current canvas as an upscaled PNG image for visual inspection.' It specifies the verb (return), resource (canvas), and format (upscaled PNG), effectively distinguishing it from sibling tools that draw, create, or list canvases.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies usage for visual inspection but does not explicitly state when to use this tool versus alternatives like pixelart_get_canvas_info. No mention of prerequisites or when not to use it, though the purpose is straightforward.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_delete_tilesetA
  3.6/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already provide destructiveHint=true and idempotentHint=true. The description adds 'from memory' context but does not elaborate on side effects like irreversibility or required permissions.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is short and front-loaded, but includes unnecessary docstring formatting ('Args:', 'Returns:') that could be streamlined. Still efficient overall.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the simple tool (one required param, no nested objects) and annotations, the description is mostly sufficient. It explains the core action and return value, though it could mention that the operation is irreversible.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  With 0% schema description coverage, the description must compensate. It only restates 'params: tileset_id.' without adding meaning beyond the parameter name and type already in the schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool removes a tileset from memory, with a specific verb ('Remove') and resource ('tileset'). It distinguishes from siblings like pixelart_create_tileset and pixelart_list_tilesets.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The phrase 'once it's no longer needed' provides implied context for when to use (cleanup). However, it does not include when NOT to use or mention alternatives like pixelart_delete_canvas.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_draw_circleA
  3.6/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already indicate mutation (readOnlyHint false), idempotency (true), and non-destructive nature. The description adds that it draws outline or filled and returns a confirmation string, but lacks details on overwriting behavior.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Extremely concise: one sentence for purpose, a single line for args/returns. No wasted words, front-loaded.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Covers core function and args, but lacks discussion of canvas bounds, error conditions, or handling of existing pixels. Adequate but not thorough.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters2/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The description merely lists parameter names without adding meaning beyond the schema (e.g., coordinate system, units). Schema has 0% property descriptions except color, so more explanation was needed.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states 'Draw a circle/ellipse (outline or filled) on a canvas,' specifying the verb and resource, distinguishing it from siblings like draw_line and draw_rect.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines2/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  No guidance on when to use this tool versus alternatives (e.g., draw_polygon, flood_fill); no exclusions or context provided.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_create_canvasA
  3.9/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  The description discloses that the tool creates a new canvas (mutation) and returns a JSON confirmation, which aligns with the annotation readOnlyHint=false. It does not mention potential side effects, error cases (e.g., if canvas_id already exists), or resource limits. The description adds some behavioral context beyond annotations (return format) but omits important edge-case behavior.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness4/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is short with a clear purpose statement upfront, followed by a bullet-like list of args and returns. It is not verbose and communicates essential information efficiently. Minor redundancy in repeating parameter names does not significantly detract.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The description specifies the canvas's purpose (single tile/sprite) and notes the return format (JSON string with canvas_id, width, height). It does not cover error handling, but given the tool's simplicity and the presence of an output schema, the description is largely complete for typical usage. Missing details like duplicate handling slightly reduce completeness.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The input schema provides detailed descriptions for all four parameters (width, height, canvas_id, background), including constraints and defaults. The description merely repeats the parameter names ('canvas_id, width, height, background RGBA') without adding new meaning. Since schema coverage is effectively 100%, the description adds no additional semantic value.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool creates a new blank pixel-art canvas and specifies it's for a single tile/sprite surface. This distinguishes it from sibling tools like pixelart_create_tileset (which creates a collection) and pixelart_import_canvas (import from external). The verb 'create' and resource 'canvas' are specific and unambiguous.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implicitly guides usage by stating it creates a blank canvas for sprites, which helps an agent decide when to use it (e.g., to start a new canvas). However, it does not explicitly mention when not to use it or provide alternatives like using pixelart_import_canvas for importing existing images. The context is clear but lacks exclusions.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_generate_paletteA
  3.9/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  The description explains the tool returns a JSON string with color codes. Annotations already declare readOnlyHint=true, meaning no side effects. The description adds no additional behavioral context beyond what annotations provide, so baseline score is appropriate.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise: two sentences plus structured Args/Returns sections. Every line adds value, with the purpose clearly stated first. No unnecessary text.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the presence of an output schema (context signals indicate 'Has output schema: true'), the description adequately covers the return format (JSON string). The tool is simple with few parameters, and the description is sufficient for an agent to understand the tool's behavior.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The description repeats parameter info from the input schema (lists style options and n_colors). Despite schema description coverage being 0% in context, the schema's property descriptions already contain the same details. Description adds no new meaning beyond the schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states 'Generate a limited, cohesive color palette for pixel art.' It specifies the tool's verb 'generate' and resource 'color palette', distinguishing it from siblings like pixelart_extract_palette which extracts palettes from existing images.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines3/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies usage for generating palettes with optional style and number of colors, but does not explicitly state when to use this tool versus alternatives like pixelart_extract_palette. No when-not or alternative guidance is provided.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_duplicate_canvasA
  4/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations show readOnlyHint=false (write), destructiveHint=false. Description adds return type but no further behavioral details. Adequate but minimal.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Two lines for purpose, two for usage, then args/returns. No fluff. Front-loaded.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Simple tool, description covers key aspects. No mention of error conditions or uniqueness constraint on new id, but adequate for basic usage.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema has 0% coverage on the top-level param, and description only lists parameter names without extra detail. Inner schema descriptions help, but not fully compensated.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  Clearly states it copies an existing canvas to a new id. Distinguishes from siblings like create_canvas which creates empty. Provides concrete use case.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  Provides a specific use case (repeated tiles) but does not explicitly state when not to use or alternative tools. Lacks exclusions.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_import_canvasA
  4/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already exist but are generic. The description adds that it loads an image and returns canvas_id, width, height, but does not disclose potential side effects (e.g., file format limits, memory usage, or error handling).

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is seven lines, includes Args and Returns sections, and is succinct without extraneous text. Every sentence adds value.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness4/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the complexity (single param with two sub-properties, output exists), the description adequately explains the tool's purpose, parameters, and return. It lacks prerequisites (e.g., file existence) but is generally complete.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The schema descriptions already cover the parameters ('Unique id to store...' and 'Local path...'). The description lists them briefly in Args but adds no new details beyond the schema. It does include the return format, which is not in the input schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states it loads an existing image file into a new canvas, distinguishing it from creating a blank canvas by specifying it's for continuing an existing sprite. The verb 'import' accurately reflects the action.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  It provides explicit context: 'Use this to continue editing a sprite that already exists... instead of redrawing it from a blank canvas.' This explains when to use this tool vs. creating a new canvas, but does not mention other sibling tools like pixelart_duplicate_canvas.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_export_tilesetA
  4.1/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already indicate this is a write operation (readOnlyHint=false) but not destructive (destructiveHint=false). The description adds the side effect of writing files to disk but does not clarify overwrite behavior, file existence, or directory creation, which would improve transparency.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is well-structured: a one-sentence summary, a clarifying paragraph, and an Args/Returns section. It is concise with no wasted words, front-loading the primary action.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the presence of an output schema (not shown but implied) and detailed parameter schemas, the description completes the picture by explaining the metadata purpose and expected output structure. It is sufficiently complete for an agent to use the tool correctly.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema coverage is high (each parameter has a description), so the description adds only modest value by summarizing parameters. It mentions 'palette (optional hex list to record)' which mirrors the schema; no additional semantic value beyond the schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description begins with a specific verb-resource pair: 'Export a tileset to a PNG file plus a JSON metadata sidecar.' It clearly differentiates from sibling tools like 'pixelart_create_tileset' and 'pixelart_set_tile' by focusing on export to disk.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description states that the metadata is meant for 'downstream engine-integration tool,' implicitly guiding when to use this tool (when integration is needed). However, it does not explicitly mention when not to use or list alternatives, slightly limiting clarity.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_set_pixelA
  4.1/5.0
  Behavior3/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  The description states basic behavior (set pixel color, return confirmation) but adds no additional behavioral context beyond annotations. Annotations already provide idempotentHint, destructiveHint, etc.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is very concise with 4 lines, front-loaded purpose, and no fluff. Every sentence adds value.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a simple tool with good annotations and output schema described as a confirmation string, the description is complete enough. No gaps identified.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema descriptions already fully cover parameter semantics (coordinates, color, canvas_id). The description adds no extra meaning, meeting the baseline for high coverage.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool sets a single pixel's color on a canvas, using specific verb and resource. It distinguishes from sibling tools like pixelart_draw_line, which handle multiple pixels.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies usage for setting a single pixel, providing clear context. However, it does not explicitly state when not to use it or mention alternatives like draw_line for lines.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_draw_polygonA
  4.3/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations indicate idempotentHint=true and readOnlyHint=false. The description adds behavioral context by explaining that the polygon can be an outline or filled based on the 'fill' parameter. It also mentions the return type ('Confirmation string'). No contradictions with annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise with five short sentences. The first sentence states the core action, the second provides usage guidance, the third lists parameters, and the last two note the return. No unnecessary words or padding.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness3/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given the tool's moderate complexity (4 parameters, one nested object) and low schema coverage, the description covers essential purpose and usage but lacks details like coordinate system, error conditions, or behavior for invalid input. It is adequate but not comprehensive.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema description coverage for the top-level 'params' property is 0%, but sub-properties have descriptions for 'color' and 'points'. The description lists all parameters ('canvas_id, points (>=3 [x,y] pairs), color, fill') and adds minimal info (minimum points). However, it does not explain the 'fill' parameter beyond its presence, and relies on the schema for detailed constraints.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states 'Draw a polygon (outline or filled) from a list of vertex points.' It uses a specific verb ('Draw') and resource ('polygon'), and explicitly distinguishes itself from sibling tools draw_rect and draw_circle by providing use cases where they fall short.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description explicitly states when to use this tool: 'for shapes that draw_rect/draw_circle can't express (roof slopes, tree silhouettes, diagonal terrain edges, etc).' This provides clear guidance on alternatives and context, making it easy for an agent to decide.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_flip_canvasA
  4.3/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already indicate idempotentHint=true and destructiveHint=false. The description adds 'in place' modification and clarifies the return is a confirmation string, complementing the annotations without contradiction.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise with four short sentences, front-loads the action, and avoids unnecessary wording. Every sentence adds value.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a simple tool with two parameters and an output schema, the description covers purpose, usage context, parameter details, and return value thoroughly. No gaps remain.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The description lists the two parameters (canvas_id, direction) and their expected values, but the input schema already provides a description for direction. The description adds no new semantic meaning beyond what the schema provides, resulting in a baseline score.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the action is to mirror a canvas horizontally or vertically in place. It provides a specific use case for pixel-art symmetry, and the tool name is distinct among siblings.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies when to use (after drawing half of a symmetrical object) but does not explicitly state when not to use or provide alternatives. It offers a clear context for usage.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_get_canvas_infoA
  4.5/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already convey read-only, idempotent, non-destructive behavior. The description adds value by stating it is 'cheaper' and 'without rendering a preview image', which are helpful behavioral details beyond the annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise: two sentences for purpose, a usage hint, then structured Args/Returns. Every sentence adds value, no wasted words.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a simple read-only metadata tool with one parameter and a clear return format described, the description is complete. It covers purpose, usage guidance, return values, and cost comparison, leaving no obvious gaps.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The single parameter canvas_id is described in the schema as 'Canvas to inspect.' The tool description only mentions it in the Args section without adding new meaning. Since schema coverage is 0% and the description does not compensate, a score of 3 is appropriate for adequate but minimal enrichment.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool retrieves lightweight metadata (dimensions, pixel counts) without rendering a preview, and it explicitly distinguishes itself from the sibling pixelart_get_canvas_preview by emphasizing it is cheaper.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description explicitly tells the agent when to use this tool: when only dimensions or whether anything has been drawn are needed, and contrasts it with pixelart_get_canvas_preview as a more expensive alternative.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_list_tilesetsA
  4.5/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false. The description adds the return format (JSON string with fields), providing additional context beyond annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Two sentences: one for the action, one for the return format. No wasted words, front-loaded with the main purpose.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  For a simple list with no parameters and an output schema indicated, the description is fully complete. It tells the agent exactly what to expect.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  No parameters exist, so baseline is 4. The description adds value by explaining the return structure, compensating for the lack of parameter semantics.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states 'List every tileset currently held in memory', using a specific verb and resource. It distinguishes this from sibling tools like pixelart_list_canvases and pixelart_create_tileset.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines4/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description implies usage for getting an overview of all tilesets. No explicit when-not-to-use or alternatives, but the context of a simple list with no parameters is clear.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_suggest_tilemap_layoutA
  4.5/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already indicate read-only, idempotent, and non-destructive behavior. The description adds context about the tool being a calculation that does not create or modify any canvas, and specifies the return format. It does not contradict annotations.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  The description is concise and well-structured: first sentence states purpose, then usage guidelines, then argument and return format. It is front-loaded and every sentence serves a purpose without redundancy.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  The description is complete for a calculation tool. It explains inputs, outputs, and workflow dependencies (calling suggest_tile_size first, using result with create_tileset). Even with the output schema present, the description covers the return fields.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters3/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  The input schema already provides descriptions for all parameters, so the baseline is 3. The description paraphrases the grouping (tile_width/tile_height plus either columns/rows or screen_width/screen_height), which adds some clarity but no new semantic information beyond the schema.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states the tool's purpose: 'Work out the grid (columns x rows) and total pixel size for a FULL tilemap.' It distinguishes from sibling tools like pixelart_suggest_tile_size by specifying that this tool is for entire levels/maps, not single tiles, and provides a workflow referring to other tools.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  The description explicitly tells when to use the tool: 'whenever the user wants an actual level/map, not a single tile or asset.' It also provides a prerequisite (call pixelart_suggest_tile_size first) and two alternative input modes (explicit columns+rows or target screen size). The output usage is also described (build with pixelart_create_tileset).

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_list_canvasesA
  4.7/5.0
  Behavior4/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds that canvases are held in memory for the session (not persistent), and specifies the return format. No contradictions.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Four focused sentences, no redundancy. The main action is stated first, followed by usage guidance and return format.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Given zero parameters, rich annotations, and an output schema described, the description covers purpose, usage context, and return value completely.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters4/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  No parameters exist, so baseline 4 applies. The description does not need to add param info.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states it lists every canvas in memory for the session. The verb 'list' and resource 'canvases' are explicit, and it distinguishes from sibling tools that create, delete, or modify canvases.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  Explicitly advises using this to recover context without relying on conversational memory, providing a clear use case and alternative. This differentiates it from tools that might otherwise be used for similar purposes.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.

• pixelart_suggest_tile_sizeA
  5/5.0
  Behavior5/5

  Does the description disclose side effects, auth requirements, rate limits, or destructive behavior?

  Annotations indicate readOnly, idempotent, non-destructive. Description adds default PPU, priority logic when category given, and fallback to 16x16. Describes return format. No contradiction.

  Agents need to know what a tool does to the world before calling it. Descriptions should go beyond structured annotations to explain consequences.

  Conciseness5/5

  Is the description appropriately sized, front-loaded, and free of redundancy?

  Well-structured: purpose first, then logic with bullet points, important warning, then args and returns. Every sentence adds value, no fluff.

  Shorter descriptions cost fewer tokens and are easier for agents to parse. Every sentence should earn its place.

  Completeness5/5

  Given the tool's complexity, does the description cover enough for an agent to succeed on first attempt?

  Covers all relevant context: default PPU, priority logic, screen resolution fallback, return format (JSON with fields), and links to related tools for next steps. Complete for the tool's complexity.

  Complex tools with many parameters or behaviors need more documentation. Simple tools need less. This dimension scales expectations accordingly.

  Parameters5/5

  Does the description clarify parameter syntax, constraints, interactions, or defaults beyond what the schema provides?

  Schema has parameter descriptions, but the tool description explains the decision logic (category takes priority, screen size fallback) that adds meaning beyond the schema, compensating for the 0% coverage metric.

  Input schemas describe structure but not intent. Descriptions should explain non-obvious parameter relationships and valid value ranges.

  Purpose5/5

  Does the description clearly state what the tool does and how it differs from similar tools?

  The description clearly states it suggests a pixel size for ONE tile, distinguishing from a full tilemap/level. It differentiates from sibling tools like pixelart_suggest_tilemap_layout and pixelart_create_tileset by specifying it is a single tile only.

  Agents choose between tools based on descriptions. A clear purpose with a specific verb and resource helps agents select the right tool.

  Usage Guidelines5/5

  Does the description explain when to use this tool, when not to, or what alternatives exist?

  Provides explicit when-to-use (suggest tile size) and when-not (never export a single tile-sized canvas as whole tilemap). Suggests next steps: pixelart_suggest_tilemap_layout and pixelart_create_tileset.

  Agents often have multiple tools that could apply. Explicit usage guidance like "use X instead of Y when Z" prevents misuse.