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

With no annotations, the description carries the full burden and does disclose useful traits: the reel is generated automatically each evening (so today's clips appear late) and only 7 days are retained. It says nothing about the return format for a media tool (URLs vs. embedded clips), size, or any auth/quota constraints.

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?

A single front-loaded sentence defines the artifact first, then how it's built, then the one parameter constraint. The parenthetical content examples add selecting color at low cost; nothing is repeated.

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 optional-parameter tool with no annotations and no output schema, the description covers what the clips are, how fresh they are, and how far back you can ask. The main remaining gap is what the caller actually receives (links, files, list of moments).

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 0% and the pattern is the only constraint, but the description compensates: it marks 'day' as optional, gives the exact YYYY-MM-DD format, and states the valid window is the last 7 days. Only the default behavior when 'day' is omitted (presumably today) is left implicit.

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 concrete resource (short video clips of the day's liveliest trout-cam moments) and how they are produced (auto-picked from the camera's event log each evening). That distinguishes it from live-view siblings like trout_now and narrative ones like trout_diary, though it never uses an explicit retrieval verb such as 'returns' or 'fetches'.

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 'Optional day YYYY-MM-DD (last 7 days)' note implicitly tells the agent when the parameter is worth setting and what window is valid. There is no explicit when-to-use/when-not-to-use guidance and no named alternative for other use cases, so the routing is only implied.

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