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

Annotations already mark it read-only/idempotent, and the description adds meaningful behavior: login required, ID numbers never decrypted, registered-account phone masked to last 4 while form-entered phone is returned, and not to recite the full contact string in conversation unless requested. It also discloses the 404 for a submissionId outside the activity. 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.

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

Though long, the description is organized into clearly labeled sections (when, chain, caveats) and every sentence carries operational value. The key scoping fact—contact info is only decrypted here—is front-loaded. For a privacy-sensitive tool, this density is appropriate, not bloated.

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 only two simple parameters and no output schema, the description covers all an agent needs to invoke and use it correctly: exact triggers, chain inputs, masking rules, privacy behavior, error condition, and the returned user.id condition for the conversation sibling. Nothing material is missing.

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 descriptions already cover both parameters (slug and submissionId, with source via list items). The description adds the validation constraint that submissionId must belong to the given activity or return 404, and reinforces the chain relationship to list_signup_submissions. This modest addition above the 100% schema coverage merits a 4.

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?

Description states the tool fetches one signup submission's full answers and decrypted contact info (WeChat/email/phone), which matches name and title. It explicitly differentiates from list_signup_submissions by saying that list excludes contact details by default. The purpose is unmistakable.

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 '何时用' section gives precise trigger conditions: user explicitly asks to contact the person, get WeChat, or see what they submitted. It also provides a full chain listing list_signup_submissions for locating the row, review_signup_submission for disposition, and start_conversation with a condition (only if registered user via returned user.id). This clearly tells the agent when to use it and when to use alternatives.

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