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

Annotations already declare readOnlyHint=true, destructiveHint=false, idempotentHint=true, so the safety profile is covered. The description adds real value beyond that: it discloses the return shape (user id + name + role), enumerates the possible role values plus custom roles, and reveals a non-obvious behavioral quirk — the project owner is always injected as the first row with role=OWNER regardless of ProjectMember table entries. Pagination behavior is the only notable omission.

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 tight sentences, front-loaded with the scope and the sibling exclusion. Every clause earns its place — scope, return shape, and the owner-insertion edge case are all actionable. No filler or restatement of the tool name.

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 carries the return-value burden and does so: field list, role enumeration, and the owner-first ordering quirk. Combined with annotations covering the safety profile and a 100%-covered single required parameter, an agent has everything needed to call this correctly.

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 projectId parameter is fully documented in the schema (100% coverage) and is required, so the baseline is 3. The description reinforces the scope of the id ('SPECIFIC project') but adds no format, sourcing, or constraint detail beyond what the schema already states.

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 (members of a SPECIFIC project), and immediately scopes the resource so it cannot be confused with organization-wide listings. It names the sibling it is not (list_org_members), so an agent can distinguish the two without opening either schema.

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?

Explicitly gives the when-not condition ('NOT the whole organization') paired with the alternative to use instead ('use list_org_members for that'). This is a textbook routing instruction that removes ambiguity among a large family of list_* siblings.

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