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

Annotations declare readOnlyHint=true and openWorldHint=false, so the description does not need to cover safety. It adds valuable domain-specific behavioral context: what 'Promotions' and 'Missing' mean, the implication of a silent block, and the spamScore unit convention. This goes beyond structured fields significantly.

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?

Front-loads what is returned and its components. Every sentence adds distinct value: first sentence lists report sections, subsequent sentences define key terms and units. No redundancy or filler.

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 burden of explaining return values, and it does so thoroughly for the main report sections. However, it could be more complete by mentioning pagination or limits, though for a single-run retrieval those are likely not applicable. The tool is complex and the description provides substantial context.

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%, so the schema already documents the single 'id' parameter fully. The description does not add parameter syntax or format details, which is acceptable given the high coverage. Baseline 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?

States a specific verb (Returns), resource (one inbox placement run), and the full report content. Clearly distinguishes from siblings like list_inbox_placement_runs by specifying singular run retrieval, and no sibling tool retrieves a single run with this detailed report.

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?

Implies usage by mentioning 'from list_inbox_placement_runs' but doesn't explicitly state when to use this vs list_inbox_placement_run_results or list_inbox_placement_tests. The context of retrieving a single run is clear from the description, but no direct alternatives or exclusions are provided.

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