reels_catalog

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

Annotations already declare readOnlyHint=true, destructiveHint=false and openWorldHint=false, so safety is fully covered by structured data. The description contributes useful extras beyond that — a cost signal ('Small response') and the existence of a separate schema resource to fetch on demand — but says nothing about caching, freshness, or how the catalog relates to actual operations.

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 what is returned and followed by the cost/usage caveat. No filler or restatement of the tool 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 zero-parameter read-only tool with annotations and no output schema, the description covers the essentials but leaves the agent guessing what a 'workflow' entry contains and whether this should be called before first use of the reels_* family. A single clause on the recommended calling sequence would close the 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?

The input schema is an empty object with zero parameters, so there is nothing for the description to disambiguate. Baseline of 4 applies; the description correctly does not invent parameters.

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 says it reads 'supported scene features, limits, and the workflow,' which tells the agent roughly what comes back, but 'scene features' is opaque and nothing distinguishes this from siblings like reels_timeline or reels_create that likely also expose workflow/config knowledge. The verb+resource is present but generic, so it lands at minimum-viable clarity.

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?

'Request the schema resource only when needed' implies a call-sparing posture and hints this is a discovery/priming tool, but it never states the condition under which it is needed or names any sibling as the alternative. Usage is implied rather than prescribed.

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