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

Goes well beyond the read-only/idempotent annotations: it discloses that no figure, rating or order is added, that cross-unit comparisons are flagged via units_differ.sentence because conversion requires a moral judgment, and that modeled figures carry guaranteed: false. These are exactly the behavioral caveats an agent needs before presenting results.

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 purpose then follows with caveats and output contract; every clause carries information. The decision_brief enumeration is dense but each item (donate_url, evaluator fund, comparison page, modeled flag) is distinct content, not padding.

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 carries the return-value burden and does so (units_differ, decision_brief contents, modeled/guaranteed flags). Minor gaps remain around error behavior for unknown or duplicate ids, but nothing essential for correct invocation 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 coverage is 100% and the single parameter already documents comma-separated ids with a minimum of two. The description only reinforces the org_* id format and the count minimum, so 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 ('side-by-side claims, recommendation tiers, and trust for two or more org_* ids'). The multi-org scope and listed outputs distinguish it from single-entity siblings like get_org, get_trust, and list_charities without ambiguity.

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 'two or more org_* ids' constraint implies when the tool applies, and the units_differ note explains a comparison-specific situation. However, it never names an alternative (get_org for one charity, recommend_charity for a single pick) or states exclusions, so routing still requires inference.

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