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

Annotations already declare readOnly/idempotent/non-destructive, so the safety bar is low, but the description adds the crucial behavioral fact that this returns the definition and not executed data. It also adds a directive to explain results to the user. Lacks detail on failure modes for an invalid ID or whether missing scope falls back to a default.

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?

Four short sentences, front-loaded with the purpose and return contents, then usage, then the alternative-tool route. Every sentence carries information an agent needs to select or call the tool.

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 does its job by enumerating what the response contains and warning that it is a definition rather than data. The only omission is the meaning of projectId and any error behavior for an unresolved report ID.

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 coverage is 50%: reportId is already documented in the schema, and the description largely repeats it (list_insights_reports / Insights URL). projectId is undocumented in both the schema and the description, a real gap the description does not compensate for. 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 and resource ('Read an existing report's definition') and enumerates exactly what is returned: formulas, SQL, data sources, permissions, resolved default scope. Explicitly distinguishes itself from the sibling query_insights_report, so an agent can route 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?

Gives explicit when-to-use (need the report definition; ID comes from list_insights_reports or the Insights URL) and when-not-to-use ('Call query_insights_report for data'), naming the alternative directly. Nothing is left to inference.

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