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

Annotations already declare readOnlyHint=true, so the safety profile is covered and the burden on the description is lower. The description adds the underlying endpoint (GET /destinations/{id}) but says nothing about 404/error behavior or authentication, so it is only minimally additive.

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 is largely endpoint mapping rather than agent-facing semantics, which is minor filler but still compact overall.

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 one-parameter read tool with no output schema and annotations covering safety, the description supplies everything needed to invoke it correctly. Only edge-case behavior (not-found, auth) is left unstated, which is a minor gap.

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% and the single 'id' parameter is fully documented as a numeric id passed as a string. The description restates 'by id' without adding format, validation, or lookup semantics, so the 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 ('Get') and resource ('a single destination connection') qualified by 'by id', which distinguishes it from census_list_destinations through the word 'single'. It does not explicitly name the sibling alternative, so it falls just short of a 5.

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?

Usage is implied by 'single ... by id' — fetch one destination when you already have its id — but there is no explicit when-to-use vs when-to-use-list guidance and no stated prerequisites. The REST endpoint mapping adds orientation but not selection guidance.

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