Analyse an X creator

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

Annotations already declare readOnlyHint, idempotentHint, openWorldHint and destructiveHint=false, so the safety profile is covered. The description adds genuinely non-derivable context — the env-var auth requirement for API mode, that manual mode performs no network calls, and that the price range comes with 'the exact formula and assumptions'. However it doesn't disclose error behavior (invalid handle, insufficient posts) or the response shape beyond a field list.

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 dense paragraph that front-loads the deliverable and then the modes, saving, and return-value note. Every clause carries information, though the mid-sentence accumulation of output fields and the formula/assumptions aside make it slightly heavy to scan.

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?

With no output schema, the description does the important work of naming what is returned (profile fields, engagement metrics, price range with formula, plus a `narrative_prompt` the agent is expected to use) and clarifies that nothing is persisted. Given zero required parameters and nested objects, the main missing piece is the mutual exclusivity of username vs manual.

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 67%, so username and the manual sub-object are already documented in the schema; the description only restates that manual takes 'profile+posts'. `max_posts` is undocumented in both schema and description, and the fact that the top-level inputs are effectively either/or (username XOR manual) is implied but never stated as a constraint. Baseline 3 is appropriate given the schema does most of the work.

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 specific verb+resource ('Builds a structured sponsor profile for an X creator') and enumerates exactly what the profile contains (niches, audience, content style, engagement metrics, price-per-post range). It also names the sibling it is not — 'Saves nothing (use save_creator_profile)' — so an agent can distinguish it without opening another schema.

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?

Explicitly presents the two operating modes: X API source (requires X_BEARER_TOKEN) or `manual` profile+posts with 'No network'. It also routes the persist step to save_creator_profile. It stops short of stating when to prefer manual over the API (e.g. rate limits, handle not found), so it is clear context without full exclusions.

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