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

Annotations already cover read-only, idempotent, and non-destructive traits, so the bar is lower. The description adds genuinely useful context beyond them: no authority or persistence is created, no balance is verified, and existing credentials/signed grants are still required for any real action. It stops short of describing the preview's structure or edge-case behavior.

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 purpose is front-loaded, but the same point is restated at least three times ('creates no authority,' 'This adapter grants no authority,' 'grants no authority and never supplies server credentials'). The redundancy consumes budget that could have explained the 13 undocumented parameters.

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 13-parameter, no-output-schema computation tool with 0% schema coverage, the description must be substantially more complete. It explains the trust boundary well but gives no field-level guidance on units, formats, or how the preview is shaped, which are exactly what an agent needs to call it correctly.

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% across 13 required parameters, so the description must carry parameter meaning. It only groups fields into conceptual families ('scope, budget, usage, expiry and per-action fee limits') without explaining units (minor), the as_of evaluation time, or product-key matching, leaving most semantics undocumented.

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 states a specific verb-plus-resource: 'Evaluate ... scope, budget, usage, expiry and per-action fee limits' and clarifies the output as a 'would-allow or would-deny preview.' It distinguishes itself as a pure computation ('creates no authority') rather than an authority-granting tool, though it never names the closest sibling (wever_agent-budget-guard) to route the agent 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?

Usage is implied through the operating boundary: use this for a non-binding preview, since it 'creates no authority and verifies no account balance' and 'existing credentials and signed grants remain required for any separate action.' However, there is no explicit when-to-use/when-not statement or named alternative among the many siblings, leaving the agent to infer the boundary.

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