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

Annotations already declare readOnlyHint=true, so the safety profile is covered. The description adds the raw HTTP endpoint and the shape of the returned summary fields, which is useful context, but says nothing about auth requirements, error cases when the id is unknown, or whether the underlying data is cached.

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 compact sentences with zero filler; the purpose is front-loaded and the endpoint reference is a short, useful appendix. Nothing needs to be trimmed.

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 usefully enumerates the key fields returned (platformKey, status, sourceType, lastSync), so an agent knows what it will get back. Given a simple 2-param idempotent read with annotations covering safety, that is nearly sufficient, though pagination/error behavior is not addressed.

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 both parameters (companyId, connectionId) are already documented as UUIDs in the schema. The description adds slightly by mapping them into the REST path /companies/{companyId}/connections/{connectionId}, but contributes no format or constraint detail beyond the schema. 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 ('Fetch a single data connection by id') and enumerates the returned fields, which distinguishes it from the list-style siblings. It stops short of naming codat_list_connections as the contrasting alternative, so differentiation is implied rather than explicit.

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 phrase 'by id' implies usage when a specific connectionId is already known, which is the natural inverse of the list tool. However, there is no explicit when-to-use or when-not-to-use guidance, and no reference to sibling tools like codat_list_connections or codat_get_data_status.

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