tls_certificate_info

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

With no annotations, the description carries the full burden and does most of it: it discloses the side-effect profile ('Makes one TLS handshake and sends no application data'), the cost (1 quota unit), and the latency range (1-10 seconds). It also notes that SANs carry their own scope verdict, which is non-obvious output behavior. It stops short of describing failure behavior for unreachable hosts or invalid chains.

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?

Three sentences, all front-loaded: purpose first, then side-effect/cost profile, then the SAN labelling note. Every clause contributes new information and nothing is repeated from the schema or name.

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?

An output schema exists, so return values need no elaboration, yet the description still summarizes them usefully. The cost model, latency, handshake-only side effect, and scope requirement give an agent everything needed to decide to call this and to interpret the result.

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 both parameters are already documented in the schema (host as 'Hostname in scope', port as 'TLS port' with default 443). The description reinforces the scope constraint on the host but adds no format, syntax, or edge-case detail beyond the schema, so the baseline of 3 applies.

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?

Specific verb (retrieve and parse) plus resource (the TLS certificate a host presents), and it enumerates the exact fields returned: subject, issuer, validity, SANs, key type, chain validation. The phrase 'a host in scope presents' implicitly separates it from certificate_transparency, which reads logs rather than performing a live handshake.

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: an agent infers this is the tool for inspecting a live endpoint's cert, and the 'in scope' wording hints at a get_scope prerequisite. No alternative is named and no when-not condition is given, so the agent must infer the boundary with certificate_transparency and http_headers_audit on its own.

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