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

With no annotations, the description carries the full behavioral burden. It usefully discloses the nightly cadence, Mountain Time, and latest-entry default, but does not state read-only safety, permission needs, or what happens for missing or out-of-range dates.

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 with no wasted words. The resource and the parameter behavior are both front-loaded.

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 simple one-parameter read tool with no output schema, the description provides enough context to call it correctly and understand the content. It does not describe the return shape in detail, but the low complexity makes that 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?

The single date parameter has 0% schema description coverage, and the description compensates well by stating it is optional, its YYYY-MM-DD format, Mountain Time, and the default to the latest entry. It stops short of explaining date-range or error semantics, but is strong for one parameter.

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 identifies a specific resource, Old Gravel's nightly diary, and the title supplies the read verb. It is clear what content the tool returns, though it does not explicitly differentiate itself from siblings such as talk_to_trout or trout_now.

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 only usage cue is that the date is optional and defaults to the latest entry. There is no guidance on when to choose this tool over sibling tools or when not to use it.

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