list_profiles

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

readOnlyHint=true already tells the agent this is a safe read, so the bar is lower; the description still adds value by disclosing the authentication prerequisite and the non-obvious fact that start_login does not grant access. It stops short of describing pagination or ordering of the returned list.

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?

Two short blocks, front-loaded with what the call returns, followed by the access requirement. Every sentence carries information; the ACCESS paragraph is slightly verbose in its procedural detail but earns its place given the auth gate.

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 parameters and no output schema, the description supplies everything an agent needs: the scope of the result set, that it is a safe read via annotations, and the account/key prerequisite. Nothing material is missing for a correct invocation.

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, which is the baseline-4 case; there is nothing for the description to disambiguate beyond confirming the listing is account-wide rather than filtered.

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 (List) and resource (profiles) scoped to the authenticated account, and clarifies the return set includes primary and secondary profiles. It does not, however, distinguish itself from nearby siblings like get_profile or get_my_profile, so an agent must infer when a single-profile fetch is preferred over this bulk list.

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?

It gives a real prerequisite ('needs a Proof account', set PROOF_API_KEY and restart the server) and explicitly rules out start_login as a way to unlock it, which is genuinely useful. But it never says when to choose list_profiles over get_profile, get_my_profile, or list_profile_templates, so alternative selection is left to inference.

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