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

With no annotations, the description carries the behavioral burden. It discloses token-visible project scoping, filtering by username/display name/email, and the critical behavior that mentions match username but not display name. Ordering and return shape are not mentioned, but this is adequate for a non-destructive list tool.

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?

Three sentences with no fluff: scope, filters, and usage semantics. Key constraints are front-loaded and every sentence earns its place.

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?

Given 4 optional params, no output schema, and no annotations, the description covers the core use case, filtering, and the subtle username/display-name distinction. It doesn't explicitly list return fields, but the fields named in text and schema provide sufficient guidance.

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 baseline is 3. The description adds meaningful cross-tool semantics beyond the schema: the [~username] mention syntax, the username-not-display-name matching rule, and how to pass the same value as assignee.

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 action (list) and resource (users), defines the population as members of projects visible to the token, and clearly differentiates from sibling tools by tying to assignment/mention use case.

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 concrete context for when to call: when you need users to assign work to or mention, with guidance on how to reuse the returned usernames in mentions and as assignee. Doesn't name exclusions, but no close alternative exists among siblings.

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