impact_explain

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

Beyond the readOnly/destructive annotations, the description discloses substantial behavior: a hard character budget with an env-var override, compact grouped rendering with an explicit partial-view notice ('never a silent cut'), AND-combined filters, addresses always rendered in full detail, and lexical sorting for deterministic output. These are exactly the non-obvious traits that would otherwise surprise an 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?

Despite its length, every sentence earns its place: purpose, input modes, output format, budget behavior, filter semantics, and determinism. The most decision-relevant info (what it does, what to provide) is front-loaded, and no sentence repeats the schema or annotations.

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 tool with 7 optional parameters, an output schema, and meaningful failure/edge behavior (budget overruns, partial views), the description is complete. An agent can correctly select an input mode, choose filters, and predict the response shape without opening the schema or chasing external docs.

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 0%, so the description carries the full burden — and it delivers. All 7 parameters get meaningful semantics: manifest_handle's provenance, manifest_path's on-disk nature, manifest as inline document, severity with an example value, module_prefix as address prefix, resource_type with an exact-match caveat and example, and addresses as the guaranteed full-detail path. It fully compensates for the empty schema.

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?

Opens with a specific verb-plus-resource statement ('Explain an Impact Manifest in plain language') and then details the output contents (verdict, findings, safe-if checklist, unverifiable items), making the tool's job unmistakable. The explain/emit verb pair cleanly distinguishes it from the only sibling, impact_emit.

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 gives clear context on the three mutually exclusive input modes (manifest_handle 'from impact_emit', manifest_path on disk, manifest inline) and how the optional filters narrow the view. It stops short of an explicit when-not-to-use statement relative to impact_emit, but the pointer that manifest_handle comes 'from impact_emit' effectively orients the agent to the sibling's role.

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