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

Annotations already declare the non-read-only, non-destructive, non-idempotent profile, and the description genuinely adds to that: 'The source file is never changed' tells the agent edits are written to a new output rather than mutating input, and the preserve_palette default is disclosed. It does not cover where output lands or how variants interact.

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

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

Four short sentences, each carrying distinct information, with the core action front-loaded. No filler, though the default-behavior notes could be consolidated.

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

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

For a 10-parameter tool with zero schema descriptions and no output schema, the description is thin: it never says where results are written, how 'variants' produces multiple outputs, what 'background' modes do, or how 'palette' relates to 'preserve_palette'. An agent could call it but would be guessing on most options.

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

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

Schema coverage is 0% across 10 parameters, so the description carries the full burden, but it explains only two behaviors: width/height defaulting to source dimensions and preserve_palette defaulting true. Seed, palette, variants, background (the sole enum), output_dir, and prompt semantics are all left undocumented.

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

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

States a specific verb and resource: 'Edit an existing sprite with an instruction.' It clearly distinguishes the operation from generating or transforming a sprite, though it never names the siblings (generate_sprite, inpaint_sprite, rotate_sprite) that an agent would choose between.

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

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

Usage is only implied: 'existing sprite' suggests this is the tool for modifying an already-created asset. There is no explicit statement of when to prefer it over inpaint_sprite or rotate_sprite, nor any prerequisites (e.g., the file must exist).

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

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

Annotations already declare readOnlyHint=false, destructiveHint=false, idempotentHint=false, and openWorldHint=false. The description usefully adds that output is written to a unique directory and surfaced as a PNG preview, but says nothing about latency, cost of variants, or how seeds affect reproducibility.

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

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

Three short sentences, front-loaded with what the tool produces, followed by the one non-obvious constraint and the return behavior. Nothing is padded.

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

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

With 8 parameters, 0% schema coverage, and no output schema, the description leaves most inputs (seed, palette, variants, background, output_dir) undocumented. The output preview note is helpful but the input surface is largely unexplained.

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

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

Schema description coverage is 0% across 8 parameters, so the description must carry the load. It only restates width/height bounds (already in the schema) and ignores seed, palette, variants, background, and output_dir entirely.

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

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

States a specific verb and resource ("Generate ... pixel-art sprites from a prompt") and mentions it can produce multiple results. It's clearly the creation tool among siblings like edit_sprite, inpaint_sprite, and rotate_sprite, though it never names those alternatives explicitly.

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

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

"From a prompt" implies use this when creating from scratch rather than modifying an existing sprite, which is the only usage signal. There is no explicit when-to-use/when-not guidance relative to edit_sprite or inpaint_sprite.

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

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

Annotations already indicate this is a non-readonly, non-destructive, non-idempotent operation. Beyond that, the description usefully discloses compositing behavior: the patch is clipped to the binary mask, source pixels outside the mask are preserved, and overlay_path saves transparent patch and composite PNGs.

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

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

The description is three sentences, front-loaded with the core action, and each sentence adds relevant information about constraints or output behavior. There is little wasted text.

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

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

For a 10-parameter generation tool with no output schema and 0% schema description coverage, the description covers the central operation and compositing behavior but leaves many parameters undocumented. It is minimally viable but incomplete for reliable invocation across all options.

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

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

Schema description coverage is 0% across 10 parameters. The description only addresses image_path, mask_path, and overlay_path, leaving prompt, seed, variants, palette, background, output_dir, and preserve_palette unexplained.

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

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

The description states a specific verb and resource: inpainting a selected region of an existing sprite. It is clear what the tool does, though it does not explicitly distinguish itself from sibling tools like edit_sprite or generate_sprite.

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

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

Usage is implied by the operation: use this when you have an image and a mask selecting the region to regenerate. However, the description does not explicitly say when to use this versus edit_sprite or generate_sprite, nor does it state when not to use it.

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

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so safety is covered. The description adds genuinely new context that only ownership-marked metadata files are read and other files are ignored, but says nothing about result ordering, pagination, or what happens with an empty result.

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

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

Two tight sentences with the core purpose front-loaded and the filtering constraint second. Nothing redundant or padded.

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

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

For a simple listing tool this is close, but with no output schema and 0% schema description coverage, the description should at least explain what output_dir changes and what the listing returns. The ownership-marker detail is helpful but leaves the listing's shape and the meaning of its only substantive parameter undocumented.

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

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

Schema description coverage is 0% and the description never mentions either parameter. Neither 'limit' (default 20, max 100) nor 'output_dir' (null default, semantics entirely unexplained) is clarified, so the agent gets no help on what output_dir actually scopes.

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

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

States a specific verb and resource ("List recent MCP-owned generation metadata") with a clear scope qualifier. It doesn't explicitly contrast itself with siblings like generate_sprite or spriteloom_status, but the read-only listing purpose is unambiguous.

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

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

No statement of when to use this versus siblings (generate_sprite, edit_sprite, spriteloom_status) or when not to. The note about ignored arbitrary files is a scoping constraint on behavior, not usage guidance, so the agent must infer intent.

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

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

Annotations already declare non-read-only, non-destructive behavior. The description adds useful context: the operation invokes the model, does not rotate pixels, and never changes image_path. It still omits where generated outputs are written and whether new files are created.

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

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

The description is three short sentences, front-loaded with purpose and followed by key caveats. It wastes little space, though the instruction to provide subject and view could be more tightly integrated.

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

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

For a 9-parameter tool with no output schema and zero schema descriptions, the description is too sparse. It clarifies the core operation but leaves most parameters and the output behavior undocumented, so an agent cannot fully understand the call from the definition.

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

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

Schema description coverage is 0% across 9 parameters, so the description must compensate. It only mentions subject, view, and image_path, leaving seed, palette, symmetry, variants, background, and output_dir completely unexplained.

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

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

The description states a specific operation: re-viewing a sprite from a requested direction using SpriteLoom's instruction mode, and clarifies that it does not rotate pixels. It is distinguishable from generic generation, though it does not explicitly contrast with siblings such as edit_sprite or generate_sprite.

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

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

Usage is implied: use this when you need a new directional view of a subject, and note that it is model-based rather than pixel manipulation. However, there are no explicit exclusions, prerequisites, or named alternatives to guide selection among the sibling sprite tools.

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

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

Annotations already declare readOnlyHint, idempotentHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description still adds real value by asserting the call has no side effect on the model and by enumerating what is returned (state, backend, WebSocket URL, process ID, ownership).

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

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

Two short sentences with zero filler, and the core purpose plus the key non-behavior ('never starts the model') are front-loaded.

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

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

For a zero-parameter read with no output schema, the description covers the essential return fields and the no-side-effect guarantee. It stops short of describing the shape or possible values of those fields, but that is a minor gap for this complexity level.

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

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

The tool takes zero parameters, so there is nothing for the description to disambiguate; baseline 4 applies. No misleading parameter hints are present.

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

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

States a specific verb ('Read') and resource ('local SpriteLoom service state'), and makes clear it is a pure read that never starts the model, which separates it from stop_service and the generation siblings. An agent can identify the tool without opening the schema.

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

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

The phrase 'never starts the model' implies this is the safe way to inspect state before acting, but the description never explicitly says when to call it versus start/generate tools. Usage is inferable rather than stated.

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

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

The annotations already declare idempotent=true, destructive=false, and readOnly=false, so the safety profile is largely covered. The description adds useful behavioral context about the shared service and automatic idle timeout, though it does not state what happens to in-flight generation work.

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

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

Two sentences, front-loaded with the action and followed by the relevant shared-service context. There is no wasted text.

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

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

For a zero-parameter service-control tool with rich annotations, the description is nearly complete. The only meaningful gap is whether stopping interrupts active sprite-generation requests.

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

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

The tool has zero parameters, so there are no parameter semantics to explain. The empty schema is sufficient, and baseline credit applies.

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

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

The description states a specific verb and resource: 'Explicitly stop the shared headless SpriteLoom service.' It also clarifies scope by noting that generation tools share the service, which distinguishes this control action from the generation siblings.

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

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

It gives clear usage context by contrasting explicit stopping with the default ten-minute idle shutdown. However, it does not name a specific alternative sibling such as status or explain situations where stopping would be inappropriate.

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