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

Annotations declare readOnlyHint=false, openWorldHint=true and idempotentHint=true, so the safety profile is mostly covered. The description adds genuinely non-obvious behavior: the response carries a per-account verdict, net confidence on a 0–1 scale and evidence, and the call costs 1 credit only when at least one account is found. That cost conditionality effectively explains why the tool is not marked read-only, which is valuable context beyond the annotations.

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 core action and input, followed by return shape and pricing. Every clause carries information: platforms, output fields, confidence range, and billing rule. No filler or repetition of the title.

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 correctly takes on the burden of describing the return value (creator, accounts with verdicts, confidence, evidence, websites) and adds the credit model. Minor omissions remain: no mention of behavior on unsupported or malformed URLs, empty-result shape, or authentication/credit requirements. For a one-parameter lookup this is close to complete.

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?

There is a single parameter with 100% schema description coverage, and the schema already states it must be a profile page and not a post, reel, short or video. The description's only addition is enumerating the supported platforms (Instagram, TikTok, YouTube, X), which is marginal. Baseline 3 applies since the schema does the heavy lifting.

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 and resource ('Find a creator's accounts') plus the exact input form (one Instagram, TikTok, YouTube or X profile URL). The output scope is also named (accounts, verdict, net confidence, evidence, websites), so an agent knows both what goes in and what comes out. No sibling (check_balance, get_batch, start_batch) overlaps in purpose, so there is no ambiguity to resolve.

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: the phrase 'from one Instagram, TikTok, YouTube or X profile URL' tells the agent the acceptable input situation, and the schema reinforces that posts/reels/shorts/videos are out of scope. There is no explicit when-to-use versus an alternative and no statement of prerequisites such as needing credit balance. Adequate but with clear gaps.

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