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

Annotations already declare readOnly/idempotent/non-destructive, but the description adds substantial context beyond them: PII is returned in plaintext (phone/WeChat/email), it is scoped to the owner only and never relayed to third parties, sensitive ID fields are not retained, and isFile=true returns filename only with no address. That is rich behavioral disclosure.

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?

Front-loaded with the login requirement and purpose, then the sibling chain, then caveats. The bracket labeling aids scanning, though the single dense paragraph packs several distinct disclosures that could be slightly more digestible.

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 no output schema, the description must characterize the return value, and it does: it names the PII returned, the isFile-only-filename rule, and the sensitive-field exclusion. Combined with the layer-scoping note, an agent has everything needed to call and interpret it.

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 0 parameters, so the baseline is 4. The mention of isFile=true describes a returned field rather than an input parameter, which is useful for interpreting output but does not change the fact that there is no parameter surface to clarify.

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+resource: read the caller's own cross-form signup reuse profile. It explicitly separates itself from the sibling mutators (update_my_signup_profile, forget_my_signup_answers) and from the unrelated homepage/company profile layer, so an agent can identify it without schema inspection.

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 【组合链】 line maps read→update→delete across the three sibling tools, telling the agent exactly which tool to pick for which action. It also states the login prerequisite and that this layer is independent of homepage/company, so when-not-to-expect-side-effects is covered.

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