subdomain_takeover_check

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

With no annotations provided, the description carries the full burden of disclosure. It accurately describes the operation as a read-only check and details the technical mechanism (dangling CNAME checks) and scope (S3, GitHub Pages, Heroku). However, it does not disclose any potential side effects, network behavior, rate limits, or what constitutes a successful output, which could be useful for the agent.

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 description is two sentences long and immediately front-loads the core purpose. The first sentence is short and direct, and the second adds technical precision by naming the technologies involved. It earns its place without wasteful clauses, though it could be argued it is slightly less dense than the absolute most optimal examples.

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?

Considering the tool's low complexity (simple check), the presence of an output schema, and 100% parameter coverage, the description sufficiently covers the necessary context for an agent to use it correctly. It explains the 'what' and the 'how', and the existence of a separate batch sibling implies that usage logic is delegated there. No critical gaps are apparent.

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%, meaning all four parameters ('subdomain', 'target_id', 'scope_exclude', 'scope_include') have descriptions in the schema, establishing a baseline of 3. The description text itself does not add extra clarity beyond what the schema already provides, and the parameters are straightforward for this context.

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 uses a specific verb ('Check') and a clear resource ('a subdomain for takeover opportunities'). It clearly defines the scope by mentioning 'dangling CNAME records pointing to unclaimed external services', which clearly distinguishes its function from siblings like `subdomain_takeover_check_batch` (handled separately).

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 implies its usage by clearly stating what it does ('Checks for dangling CNAME records') and provides context by giving examples of external services. While it doesn't explicitly state when not to use it or mention alternatives like the batch counterpart, the context is quite clear. It misses explicit exclusion guidance but covers the 'when to use' part well.

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