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

Annotations only provide low-level hints (write, not idempotent, not destructive). The description goes well beyond them by disclosing the login requirement, type-dependent privacy defaults, and the important consequence that public links are visible to anyone via get_creator. It also requires explicit user confirmation before making contact info public, which is critical behavioral context.

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 compact and well-structured: login requirement and purpose first, privacy defaults second, and a concrete example third. Every sentence contributes to a decision the agent must make, and the most safety-critical instruction is bolded and 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 4-parameter mutation tool with no output schema, the description covers the login requirement, type domain, visibility defaults, privacy caveat, and a runnable example. It does not describe the return value or duplicate-type behavior, but neither is needed to select and invoke the tool correctly. The safety-relevant information is fully present.

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%, so the baseline is 3. The description adds real value by explaining the default visibility mapping by type, the rule that public must be explicit, and the privacy exposure via get_creator. It also gives a concrete example for type, url, and visibility that goes beyond the raw schema text.

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: adding a link to the current user's profile. The qualifier '不动其它字段' clarifies this is additive rather than an update, and '当前用户' identifies whose profile is modified. This makes it easy to distinguish from remove_profile_link and set_link_visibility.

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?

Provides clear usage context: requires login, adds a link to the current user, and includes a concrete example mapping user intent to parameters. It does not explicitly name sibling alternatives like remove_profile_link or set_link_visibility, nor state when not to use this tool, so it misses the full 5-level guidance.

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