get_identity_card

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

Goes well beyond the annotations: it discloses that the tool writes to exports/identity_card.md and that non-owner callers are refused when governance is enabled, which explains why readOnlyHint is false despite the benign framing. What it doesn't cover is what happens on an export collision — overwrite, versioning, or error — for a tool that writes to a fixed path.

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 information architecture is strong — purpose, owner/export surface, when to use, when not to — with the operational constraint front-loaded. The only cost is that every sentence is duplicated in Chinese and English, roughly doubling the length for an English-reading agent.

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?

An output schema exists, so return-value detail is unnecessary, and with no parameters the surface is small. The description still covers purpose, the file side effect, the authorization constraint, and the sibling alternative — 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?

The tool takes zero parameters, so there is nothing to disambiguate and no schema coverage gap; baseline 4 applies. The description correctly implies the call is fully determined by the caller's identity at runtime rather than by arguments.

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 (export) and resource (the user's portable AI identity card), plus the output format (Markdown). It also enumerates the content of the card — identity, work style, quality standards, lessons — which separates it from get_user_context without the agent needing to open any 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?

Gives an explicit trigger ('when another AI tool needs a self-contained summary') and an explicit exclusion with the named alternative ('if the current session only needs runtime context, use get_user_context'). The routing decision is fully determined by the text.

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