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

Annotations carry only openWorldHint, so the description does the heavy lifting: it discloses the return value (scan_id), expected duration (under a minute), the verified-domain gate on active tests, the cost model (free/plan scans/credits), and that github_repo contacts GitHub but never the target site. It stops short of saying whether a scan can be cancelled or what happens on an unverified domain beyond 'passive checks'.

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?

Front-loads the action and the scan_id return, then moves through timing, verification, GitHub, and cost — each sentence carries information. It is dense for a single paragraph, and the GitHub clause occupies several sentences relative to its optionality, but there is no filler.

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 compensates by naming the returned scan_id and the tools that consume it; with thin annotations (openWorldHint only), it supplies the auth/verification and cost context an agent needs. Nothing essential for a correct first call is missing.

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 mostly restates the schema for github_repo (public, or private if connected) and adds only the side-effect note that it never contacts the scanned site; the url parameter gains no extra format or validation detail.

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 ('Start a SecScan security scan of a web application') plus scope (sites the user owns or is authorised to test). It is clearly separable from siblings like get_scan_status and get_report, which it explicitly names as follow-ups rather than doing their job.

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?

Gives explicit next steps ('returns a scan_id... then call get_scan_status with wait_seconds, or get_report') and the precondition that selects behaviour (active tests only on verified domains, passive otherwise). It also warns that each scan consumes a quota unit, which is the kind of when-to-invoke guidance agents get wrong.

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