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

With no annotations provided, the description carries the full burden of disclosing behavior, and it largely succeeds: it states the exact URL fetched, a 10s timeout, validation criteria (non-HTML content type and Contact: field), and the result shape. It also explains the not_applicable outcome for absence, which is a meaningful behavioral detail beyond the name and schema.

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?

Four compact sentences each carry distinct value: purpose, usage context, technical behavior, and return format. The core purpose is front-loaded, and there is no redundant or filler content; every sentence earns its 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?

For a single-parameter network check, the description covers purpose, usage, behavior, parameter constraints, and result shapes. However, it does not specify behavior on network failure, timeout expiration, or non-conforming content type (beyond saying it requires non-HTML), which is an important gap for an audit tool where an agent may need to distinguish 'error' from 'not_applicable'.

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 description coverage is 100%, so the baseline is 3. The description adds only a small increment by showing how <domain> is interpolated into the HTTPS URL, but the schema already documents the domain as a public FQDN and rejects IPs, ports, paths, and protocol prefixes. This marginal addition does not warrant a higher score.

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 a precise verb ('Verify') and names a concrete resource ('security.txt (RFC 9116) at /.well-known/security.txt'), which makes the tool's function immediately clear. It also distinguishes itself from sibling dossier_* checks by focusing on a single, well-known disclosure channel, so an agent can tell it apart without opening the 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?

The description explicitly directs use 'in a security audit to confirm researchers have a published disclosure route' and even characterizes the absence as a '(minor) audit flag'. It does not mention alternatives or exclusions, but the stated context is unambiguous and sufficient for an agent to decide when to invoke this tool.

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