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

Annotations include readOnlyHint: true, so the read-only nature is already disclosed. The description adds valuable behavioral context: it filters to 'active' assignments, notes pagination, and specifies the REST endpoint (GET /users/me/project_assignments). No contradiction exists.

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?

The description is concise and well-structured: first sentence states the core purpose, second explains the use case, then pagination and REST endpoint. Every sentence adds distinct value, with no redundant or filler content.

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?

Despite having no output schema, the description conveys what the tool returns (active project assignments and assignable tasks) and why it's useful (finding IDs for time entry creation). Pagination is mentioned, and the REST endpoint gives a reference point. This is sufficient for a simple list tool.

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 description coverage is 100% for both page and per_page, including details like default 2000. The description only mentions 'Paginated' without adding new parameter-specific information. Since the schema fully documents parameters, a baseline of 3 is appropriate.

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 clearly states the tool lists the authenticated user's active project assignments, specifying the exact resource (project assignments) and scope (authenticated user's active). It explicitly mentions the purpose of finding project_id and task_id for harvest_create_time_entry, distinguishing it from sibling tools like list_projects or list_tasks.

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 description provides clear when-to-use guidance: 'use this to find the project_id + task_id for harvest_create_time_entry.' This names a specific scenario and references a sibling tool, but it does not explicitly state when not to use this tool or compare it to alternative list tools, so it falls short of a 5.

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