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

With no annotations, the description carries the full burden and does reasonably well: it discloses the counting algorithm (sliding window), the return shape of take (allowed, remaining, retry_after_s), and a quota limit (free 200 counters). It does not mention persistence, permissions, or cross-bot auth requirements.

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?

Highly front-loaded and dense: identity first, then a compact action/return breakdown, then two short trailing facts (sliding window, free tier). Every clause earns its place; nothing is padded.

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 4-parameter tool with no annotations and no output schema, the description covers the essentials: what it is, its actions, its return values, and its quota. Minor gaps remain around error/quota-exceeded behavior and auth, but the core picture is complete.

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 0%, so the description must compensate, and it does: it maps parameters to actions, explains the limit format ('6/6h'), and marks n as optional ('n?'). The meaning of n is still left implicit, but overall it adds substantial meaning beyond the bare 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?

States a specific resource and scope: 'Shared rate counters across all your bots', with a concrete example ('6 posts per 6h across all lanes'). This clearly conveys a distributed rate-limiting counter. However, it does not differentiate from the similarly named sibling library_rate, which likely also deals with rates.

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 rather than stated: the action list (take/peek/list) shows the operating modes but there is no explicit 'use this when...' guidance or exclusion against alternatives like library_rate or lock. An agent can infer take is for consuming quota and peek for inspection, but must reason it out.

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