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

Annotations already cover the safety profile (readOnly, non-destructive, open-world), and the description adds genuinely new operational context: no API key or signup required, anonymous limits of 60 calls/hour and 300/day per IP and session, key-based higher limits, and the anonymous fallback after monthly quota. It also discloses data handling ('normalised to SI') and licence obligations, exactly the kind of behaviour an agent cannot infer from annotations.

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?

Well front-loaded: purpose, then filter semantics, then exclusions, then operational limits. Most sentences earn their place, but 'TerraMCP is a Wrench AI service' is pure branding and the quota sentence is longer than needed.

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 does state what comes back ('source data and provenance') and covers access, rate limits, and licence caveats for a zero-required-parameter list tool. The return shape (warning fields, severity levels returned) is only sketched, leaving a minor gap.

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. The description restates the severity semantics ('1 most severe, 4 no longer in force; default 3 includes alerts') without adding syntax, format, or edge-case detail beyond the schema, so the baseline 3 applies.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?

States a specific verb and resource ('List current EA flood warnings and alerts') plus the intent ('to check active warnings for an area'), so an agent immediately knows what the tool returns. It draws a conceptual boundary with 'Not a site-specific risk assessment', which implicitly separates it from flood_zone_at_point, but no sibling is named explicitly.

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 a clear use context (checking active warnings for an area) and a negative condition ('Not a site-specific risk assessment'), which steers the agent away from point-based flood-zone tools. It stops short of naming the alternative tool to use instead, so routing is inferred rather than stated.

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