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

Annotations already declare readOnlyHint, destructiveHint=false and openWorldHint=false, so the safety profile is covered. The description adds real value beyond that by disclosing the returned fields and, importantly, a prompt-injection warning that nicknames are attacker-controlled text to be treated as data.

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 sentences, both load-bearing: the first defines the resource and its shape, the second delivers a security caveat. No filler and no repetition of the schema.

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 usefully enumerates the returned fields (id, nickname, created, last used, revoked) and warns about untrusted nickname content. Only minor gaps remain, such as ordering or pagination behavior for large owner teams.

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 single optional passport_token parameter is fully documented in the schema (100% coverage), including its fallback-header use case. The description adds nothing about parameters, which is acceptable given complete schema coverage and a baseline of 3.

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?

The description states the specific resource (passports/agents sharing your owner) and enumerates the fields returned, which is more precise than the title 'List my owner's agents' alone. It does not explicitly contrast itself with adjacent tools like whoami or create_passport, but the verb+resource is unambiguous.

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?

There is no guidance on when to call this versus alternatives such as whoami, create_passport, or remove_passport, nor any stated preconditions. The read-only annotation implies a safe inspection call, but the description itself leaves usage entirely inferred.

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