facesign-mcp

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

No annotations are provided, so the description carries the full disclosure burden. It adds real behavioral context beyond the schema: the exported app 'ships NO default chrome — every visible string comes from you' and requires FACESIGN_API_KEY for deployment, which conveys the auth precondition. However, it does not disclose side effects, idempotency on repeated calls, generation cost/latency, or any failure behavior, leaving meaningful gaps for a generation tool.

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 a single tight ~80-word paragraph that front-loads purpose, names the mandatory inputs, states the behavioral constraint (no default chrome), and closes with deployment steps. Every sentence earns its place with no filler or tautology — appropriately concise given how much detail already lives inside the schema.

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 tool this complex (16 params, nested flow graphs, 14 node types, no output schema), the description orients the agent well: it covers purpose, the three mandatory content inputs, the no-default-chrome constraint, and runtime/deployment expectations. The schema itself is extraordinarily rich (full style guides, code snippets, common-mistake lists), so the short description does not need to compensate — it adequately frames when and how to call the tool.

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 100% and every parameter already carries a detailed inline description (including extensive style guides and code contracts on landingHtml and recapHtml). The description paragraph reinforces the roles of the three required params (e.g., 'landingHtml (pre-session page)') but adds marginal semantic value beyond what the schema documents, aligning with the baseline-3 rule for high coverage.

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 opening sentence — 'Export the current FaceSign session configuration as a standalone, deployable Next.js application' — states a specific verb (export), resource (session configuration), and deliverable (deployable Next.js app). This is clearly distinct from the sibling tools (get_session, list_sessions are read operations; launch_session_ui runs a session; set_api_key configures credentials).

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 description clearly signals what inputs are mandatory ('You MUST supply landingHtml, recapHtml, and uiStrings') and how to operate the output ('Run with npm install && npm run dev or deploy to Vercel after setting FACESIGN_API_KEY'). It does not explicitly state when NOT to use this tool or name an alternative counterpart, so it stops short of a perfect 5, but the usage context is unambiguous.

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?

No annotations are present, so the description carries the full burden. It clearly communicates a read operation by using 'Retrieve' and lists the content categories returned. However, it does not disclose error behavior, permissions, rate limits, or the meaning of 'asynchronous analysis lifecycle states,' leaving some behavioral traits unexplained.

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 a single, efficient sentence that front-loads the action and resource, then enumerates the included data types without redundancy. Every phrase adds useful information.

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 one-parameter read tool with no output schema, the description provides a strong sense of the return content by listing major components (transcript, AI analysis, node reports, etc.). It is not exhaustive but gives an appropriate high-level overview. Slight ambiguity remains around the 'asynchronous analysis lifecycle states' but the tool is still usable.

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 100% with 'sessionId' already described as 'The session ID to retrieve'. The description adds no further parameter-specific meaning, so it does not exceed the schema baseline.

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 uses a specific verb 'Retrieve' with a clear resource 'FaceSign session' and enumerates the exact scope of information returned. This clearly distinguishes it from siblings like list_sessions (which lists sessions) and launch_session_ui (which launches UI).

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 context implies use when a specific session's detailed info is needed, especially after listing sessions. However, it does not explicitly state when to use this tool vs alternatives, nor does it mention exclusions or prerequisites. Sibling tools provide contrast but the description itself offers no guidance on selection.

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?

With no annotations provided, the description carries the transparency burden and does disclose meaningful behaviors: the MCP server provides NO default chrome, every visible string must come from the caller, and each page load/refresh creates a fresh session. It does not detail return behavior or lifecycle side effects, but the core behavioral traits are well communicated.

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 four sentences with zero filler: prerequisite, purpose, required parameters, and behavioral caveat. Every sentence earns its place and the most critical information (requires set_api_key) is 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?

Despite the tool's high complexity (14 params, nested flow graph, no output schema), the description orients the agent well by covering prerequisites, required inputs, and session-freshness behavior. The extensive schema descriptions handle the remaining detail, so the description is reasonably complete for launch-oriented context, though it could briefly mention what happens after launch (return/status).

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 100%, so the baseline is 3; all 14 parameters including the complex flow, landingHtml, recapHtml, and uiStrings are thoroughly documented in the schema. The description adds emphasis that the three HTML/string parameters are mandatory and that uiStrings keys are caller-invented, but this is already in the schema property descriptions, so it adds marginal value.

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 uses a specific verb+resource pair — 'Launch a local web page in the browser for a FaceSign session' — and clearly distinguishes this from siblings like get_session or list_sessions by framing it as the launch/interactive tool. It also names the three mandatory content parameters, leaving no doubt about its role.

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 description gives an explicit prerequisite ('REQUIRES set_api_key to be called first') and states what must be supplied (landingHtml, recapHtml, uiStrings), establishing clear startup context. It does not explicitly name alternatives or list when-not-to-use scenarios, so it falls just short of a 5.

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?

No annotations are present, so the description carries the behavioral burden. 'List' reasonably implies a read-only operation and 'Supports pagination via cursor' adds cursor awareness, but it does not explain response shape, default sort/limit behavior, or how the cursor should be used.

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 two sentences, front-loaded with the action and resource, and has no filler. It briefly summarizes filters and pagination without listing every parameter.

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?

Given the rich 100% schema coverage, the description is largely adequate for selecting and invoking the tool. However, with no output schema, it does not describe what the response contains beyond implying a list, and the lack of usage guidance around sibling tools leaves some contextual ambiguity.

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 input schema already documents all 9 parameters at 100% coverage, including enums. The description's mention of status, date range, and search term is a helpful summary but does not add meaning beyond what the schema already provides.

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 clearly states 'List FaceSign sessions' with a specific verb and resource, and it mentions the optional filters and pagination. It does not explicitly differentiate itself from sibling tools like get_session, though 'list' versus 'get' is a strong implicit distinction.

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?

There is no explicit guidance about when to use this tool versus get_session, export_session, launch_session_ui, or set_api_key. The description implies a listing use case but does not state exclusions or alternatives.

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?

No annotations are provided, so the description carries the full burden. It discloses session-scoped behavior, key format, and the optional serverUrl override with production default. It doesn't mention error handling or side effects but adequately explains the tool's function for a simple setter.

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 concise sentences, front-loaded with purpose and prerequisite, each sentence adds value. No redundancy or fluff.

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 2-param setter with full schema coverage, the description provides all necessary context: purpose, prerequisite, optional use case, and default behavior. No gaps.

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 covers both parameters with detailed descriptions (100% coverage). The description adds the session requirement but doesn't add significant parameter-level meaning beyond what the schema already provides. Baseline 3 is appropriate.

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 clearly states the tool's function: 'Set your FaceSign API key for this session' with a specific verb and resource. It also distinguishes itself from sibling tools by noting it must be called before any other FaceSign tools, establishing it as a setup prerequisite.

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?

Explicitly states when to call this tool ('must be called before any other FaceSign tools') and provides guidance on when to set serverUrl (only if explicitly targeting a non-default server). This clearly differentiates usage from alternatives and gives actionable instructions.

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