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

Annotations already declare the mutation profile (readOnlyHint=false, idempotentHint=false, destructiveHint=false), so the safety burden is partly lifted. The description adds useful scope — exactly one row, and the schema defaults to public — but says nothing about failure modes for a non-idempotent write (e.g. duplicate-key errors on retry) or permission requirements.

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?

Two short sentences, front-loaded with the operation and scope. The second sentence largely duplicates the schema's own note that schema defaults to public, which is minor redundancy rather than noise.

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?

An output schema exists, so return values need not be explained, and annotations carry the safety profile. However, for a mutation with a free-form nested values object, the description omits how values map to columns and what errors to expect, leaving the agent to infer write semantics.

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 all four parameters are already documented in the schema, including the public default for schema. The description's mention of the schema default simply restates the schema rather than adding format, validation, or column-mapping guidance for the nested values object.

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 gives a specific verb and resource ("Insert one row into a Cloud Postgres table"), which clearly distinguishes it from sibling mutations like projects_cloud_database_row_update and projects_cloud_database_rows_delete. It stops short of naming those siblings explicitly, so the differentiation comes from the verb choice rather than explicit routing.

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?

There is no guidance on when to use this versus projects_cloud_database_row_update, projects_cloud_database_query, or projects_cloud_database_rows. Nothing states prerequisites (table must exist, columns must match), nor what happens on constraint violations or duplicate keys.

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