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

Annotations declare a non-read-only, non-idempotent, non-destructive write; the description adds two behavioral facts annotations cannot convey: the queue-dedupe behavior (an existing waiting run is returned instead of a new one) and the monthly-allowance consumption rule for non-failing runs. No auth or failure-handling detail, but this is meaningfully beyond the structured hints.

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 action and return values, then the dedupe edge case, then the quota caveat. Every sentence contributes; the quota sentence is slightly tangential but still operational knowledge an agent needs.

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 one-parameter action tool with no output schema, the description compensates by naming the return fields, the dedupe behavior, and the quota impact. The main remaining gap is what happens if a run fails or how the project must be connected, but nothing critical to invoking it correctly is missing.

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?

One required parameter with 0% schema description coverage, so the description must carry the burden. 'On a connected project' hints that project_id must reference a connected project, but the description adds no format, source, or lookup guidance (e.g., list_projects). Only marginal value over the bare schema.

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 and resource ('Starts an authorization test run on a connected project') and names the concrete return values (run_id and status). An agent can immediately separate this from get_run_status, wait_for_run, and list_projects without opening any 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?

The dedupe rule ('if the project already has a run waiting to start, returns that run instead') gives useful implied usage context, but the description never states when to prefer this tool over siblings like get_run_status or wait_for_run, nor any prerequisites such as needing a connected project. Usage is implied rather than guided.

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