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

Goes well beyond annotations (which only say non-read-only, non-destructive, non-idempotent) by disclosing the 8-slot quota, that counting happens server-side at write time, that the 9th is refused rather than queued, and the exact error payload (slots_used/slots_max). It also discloses the audience boundary (platform-matched partners, never the wider network), which no annotation conveys.

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 sentences, each doing distinct work: what is created and to whom it is visible, the hard quota rule and its failure mode, then the next-step pointer. Front-loaded and free of restatement of the tool name.

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?

Strong on operational behavior (quota, visibility, follow-up) and there is no output schema to explain, but for a 9-parameter creation tool with zero schema documentation the description leaves key calling details — which fields make a valid signal, units for price_cents/deadline — unresolved.

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 9 parameters, so the description must carry the load; it meaningfully explains the signal_type values and implies the open/fulfilled/closed lifecycle via "OPEN signals", but says nothing about price_cents, currency, deadline (integer — what unit?), quantity, location, product, or notes. Half the payload remains undefined for the agent.

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 ("Post ... market-signal wish-bar slots") and enumerates the five signal kinds that map to the signal_type enum, so an agent knows exactly what gets created. It also implicitly separates itself from the read/list/update siblings by naming market_signal_update as the follow-up action.

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 clear usage context — signals are visible only to platform-matched partners, and the follow-up to close or fulfil is market_signal_update. It stops short of explicit exclusions or of routing the agent to market_signal_list/read for inspection, so it is strong context without full when-not guidance.

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