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

readOnlyHint=true already tells the agent this is a safe, non-mutating read, so the bar is lower. The description adds one useful detail — that the response includes the model's SQL/query — but says nothing about error behavior for a missing/non-numeric id.

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?

One compact sentence with the essential verb/resource/payload front-loaded, followed by the REST mapping. Nothing is padded, though the 'Census: GET /models/{id}' clause adds little beyond the name.

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 single-parameter read tool with annotations covering safety and no output schema, the description plus schema is nearly sufficient; the note about returned SQL/query is the key extra context an agent needs, with only minor gaps around failure modes.

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 100% and the schema description explains the id as a numeric id passed as a string. The description only echoes 'by id' and adds no format or constraint information beyond the schema, so baseline 3 applies.

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 ('Get a single model by id') and clarifies the payload includes the SQL/query, which distinguishes it from a bare metadata fetch. It implicitly separates from census_list_models by specifying a single record, though no sibling is named.

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 'by id' phrasing implies the call is for retrieving one known model, which contrasts with list_models, but the description never states when to prefer this over census_list_models or census_get_sync, nor any prerequisite such as a valid id.

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