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

Annotations already declare readOnlyHint=true, idempotentHint=true, openWorldHint=false, and destructiveHint=false, so the safety profile is covered. The description adds a useful list of returned fields, but does not describe error behavior, missing-record handling, or other behavioral context beyond what annotations provide.

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 a single efficient fragment that front-loads the resource and returned fields. It is appropriately sized for a simple get tool, though the fragmentary wording is slightly less structured than a full sentence.

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?

For a low-complexity read tool with full schema coverage and rich annotations, the description is largely complete: it signals single-record retrieval and lists the expected fields in the absence of an output schema. It could be improved with explicit when-to-use guidance or missing-record behavior, but the core definitional content is present.

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%, and the sole parameter todo_id is documented with 'todo_id from list_todos.' The description does not mention the parameter at all, so it adds no meaning beyond the schema. Baseline 3 is appropriate given the high schema coverage.

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 identifies the resource as a single to-do and enumerates the fields it contains (description, project, priority, status, due date, assignees, checklist), which is clear enough to distinguish it from list_todos. It lacks an explicit verb and does not name sibling alternatives, but the scope is clear.

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 gives no explicit guidance on when to use this tool versus list_todos or other get_* tools. The phrase 'One to-do' implies retrieval by ID, but no alternatives, prerequisites, or exclusions are stated.

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