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

Annotations already cover the safety profile (readOnly, idempotent, non-destructive, closed-world), so the bar is lower, and the description still adds real behavior: it lists what comes back (fit, prices, plan limits, trade-offs) and warns that must_have must be forwarded from a prior decide_software call or editorial scores become non-comparable. It stops short of saying how missing or ambiguous products are handled.

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?

Three short sentences, front-loaded with the when-to-use condition and example, followed by return contents and then the two hard constraints. No restatement of the name or title and nothing decorative.

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 10-parameter read-only tool with both annotations and an output schema, the description covers the decision to call it, what it returns, and the two rules that change result quality (must_have continuity, no invented priorities). Return-value detail and validation constraints are correctly left to the schema and output schema.

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 70%, so most parameters are self-documented and the description only reinforces must_have ('pass only must-haves the buyer stated') rather than adding new meaning. The example ('5 people using Gmail') implicitly gestures at seat_count and existing_tools, but team, budget, and country get no elaboration beyond their enums and patterns.

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 action and scope: compare 2 to 4 *named* products against a buyer's situation, and gives a concrete example query. It explicitly contrasts itself with the sibling decide_software, so an agent can route without inspecting either schema.

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?

Names both the trigger (comparing named products for a buyer's situation) and the exclusion ('Do not use for unnamed products; use decide_software'). It also adds an invocation rule ('Pass only must-haves the buyer stated') and an output rule ('End your answer with the ToolScout links'), leaving little to inference.

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