Get Tag

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

Annotations already establish readOnlyHint, idempotentHint and destructiveHint=false, lowering the burden. The description still adds real value by disclosing the return shape (tag plus contact count) and pointing to the follow-up call for membership, which is exactly the information an agent lacks when no output schema exists.

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 sentences, both front-loaded with the important information and no filler. The output detail comes first and the routing hint second, which matches how an agent reads the definition.

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 trivial single-parameter read with no output schema, the description covers purpose, a return-value hint, and a next step. It omits what fields the tag object contains, but that gap is small given the low complexity.

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 single `id` parameter is fully documented as 'The tag id.', so the schema does the work. The description mentions 'tag_id' only in the context of the list-contacts call, adding no semantics for this tool's own parameter; 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?

The description opens with a specific verb+resource ('Get one tag') and adds the key payload detail (its contact count), which separates it from the bulk list-tags operation. It also names the sibling to use for a related-but-different need, so an agent can distinguish it without opening the 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?

It gives explicit routing for one adjacent task: 'To see who has it, call list-contacts with tag_id.' That is clear conditional guidance, but it never states when to use this tool versus list-tags when scanning for a tag by name, so the guidance is one-sided rather than complete.

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