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

Annotations already declare readOnly, idempotent, and non-destructive, so safety is covered. The description adds value by disclosing what the call returns (treatments plus prescription templates with quantity, refills, days supply, directions), which matters given there is no output schema.

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 tight sentences, front-loaded with the core action and scope; nothing is wasted. The trailing 'Photon GraphQL: catalog' fragment is minor metadata that adds little for an agent but is brief.

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 get-by-id tool, the description covers the resource, its return contents, and the id source (via schema). With no output schema present, the return-shape hint is a meaningful completion, though permissions or empty-result behavior are not noted.

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 schema already documents catalog_id with the '(from list_catalogs)' provenance note. The description adds no syntax or format detail beyond the schema, 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'), resource ('one treatment catalog'), and scope ('by id'), and explicitly distinguishes itself from list_catalogs by being singular/get-by-id. It also names the returned contents (treatments, prescription templates).

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?

'Get one ... by id' implies the retrieval use case, and the schema ties catalog_id to list_catalogs, but the description itself states no explicit when/when-not or alternative routing. Usage is inferred rather than declared.

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