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

With no annotations, the description carries the full burden. It discloses safe read behavior ('Pure read'), determinism, lack of LLM calls, and enumerates the response components, giving the agent a clear behavioral profile. Lacks deeper edge-case details, but sufficient for a read operation.

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; the first front-loads primary use, the second packs return shape and safety traits. Zero filler or redundancy.

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?

Given no output schema, the description adequately summarizes returned fields (composite, four dimensions, tier band, signal count, timestamp) and usage modes. It omits details like limit defaults, but the schema covers those; overall sufficient for an agent to select and invoke the tool.

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 descriptions cover 100% of parameters, so the baseline applies. The description mentions the brand vs. index-top distinction but adds no syntax or semantics beyond the schema; the `limit` parameter is only documented in the schema.

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 an explicit 'Use this when...' clause tying the tool to Persimmon's deterministic momentum score for a brand or the index top. It names a specific resource (momentum index) and distinct scope, clearly differentiating from sibling tools focused on raw signals and competitive context.

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?

Provides clear use context ('when an agent needs...') and identifies both invocation modes (specific brand or index top). It doesn't specify exclusions or explicitly name sibling alternatives, but the context makes the choice apparent.

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