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

Annotations already declare readOnlyHint, idempotentHint, non-destructive, and closed-world, so the safety profile is covered. The description adds real context beyond that: "Nothing is charged by this tool" addresses billing concerns. The sentence "The sampled site stays attached as the first video" is ambiguous about whether any state change occurs, which sits uncomfortably beside readOnlyHint=true but does not clearly assert a mutation, so it is not scored as a contradiction.

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?

The paragraph is long and run-on, mixing return value, account routing, a literal sentence to speak to the user, a state note about the sample, billing, and a follow-up sign-in. Only the first sentence is front-loaded; the remaining clauses are unordered and some appear to conflict, so sentences do not cleanly earn their place.

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 one optional parameter, no output schema, and annotations covering safety, the description covers enough to call the tool in the happy path. It falls short on the claim_token contract and on clarifying whether the sample attachment is an effect of this call, which are the two things an agent would most likely get wrong.

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 one parameter, claim_token, with 0% property-level schema coverage, so the description must carry the meaning — and it never mentions claim_token or when a caller must supply it. The object-level schema note ("required when signed out") does the work instead, leaving the description adding nothing on the only input.

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 first sentence states a specific verb and return value ("Returns plan_url, the Go Rocket plan page on go-rocket.ai"), which is genuinely useful. However, the rest of the paragraph blurs what the tool actually does — it discusses sample readiness, sample attachment, and post-hoc sign-in, making it unclear whether this is a pure link getter or participates in a claim flow. Sibling differentiation is partial: it names sign_in and create_video, but not get_sample_status or get_video_sample, which the "once the sample is ready" clause implicitly requires.

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?

It does branch by situation: "Existing account? Call sign_in, then create_video" versus new account "call this once the sample is ready." That is real routing guidance. But the ordering is confusing ("Afterwards, sign in through this connector" appears to reverse the earlier branch), and it never plainly states the precondition that this is only for signed-out/new-account contexts even though the schema hints claim_token is for signed-out use.

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