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

Annotations already declare readOnly, idempotent, non-destructive and openWorld=false, so the safety profile is covered. The description adds genuine context beyond that: the interpretive caveat that hit rates are past graded predictions, not a forecast, and not investment advice — meaningful for how an agent should present results. It still omits resolution behavior for unknown authors and whether matching is fuzzy or exact.

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, front-loaded with the lookup action and its return payload before the disclaimer. The disclaimer is longer than strictly needed but earns its place as an accuracy caveat; nothing is redundant with the title or schema.

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?

There is no output schema, so the description carries the return-value burden, and it does enumerate the main fields including per-company records. Combined with annotations covering the safety profile, it is nearly complete; only edge-case behavior (no match, multiple matches) is left unspecified.

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 coverage is 100%, so the baseline is 3, but the description adds meaning the schema lacks: an author can be an X account, YouTube speaker, Substack writer and so on, clarifying that 'query' spans multiple platforms rather than being one namespace. It does not add format rules beyond the schema's '@someone or Jane Doe' example, so this is a modest bump rather than full compensation.

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 names a specific verb and resource ('Looks up one tracked author') and pins the scope to a single entity by handle or name, which implicitly distinguishes it from list-style siblings such as get_top_authors. It also enumerates what comes back (tier, graded predictions, hit rate, most-discussed companies), so an agent knows exactly what the call yields.

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?

Usage is implied rather than stated: 'one tracked author' signals single-entity lookup, but there is no explicit when-to-use, no exclusion naming get_top_authors as the multi-author alternative, and no guidance on what happens when the query matches an untracked or ambiguous author. The agent must infer routing.

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