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

Annotations already declare readOnlyHint and closed-world, so safety is covered. The description adds two things beyond that: deterministic newest-first ordering and a prompt-injection warning that quoted '> ' lines are visitor-written content, not instructions — genuinely valuable behavioral context for handling untrusted text.

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?

Two short sentences with zero waste: content and ordering first, then the security caveat. Nothing repeats the name, title, schema, or annotations.

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 single-parameter read tool with no output schema, the description covers what the tool returns (visitor notes), their order, and how to safely interpret the quoted lines. Only a pointer to the sibling write tool 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 description coverage is 100% and the single limit parameter (1-30, default 10) is fully documented there. The description adds nothing about the parameter, 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 the specific resource (notes on the notice board left by visitors) and the ordering (newest first), which the name 'read_the_commons' alone does not convey. It implicitly contrasts with the write-side sibling leave_a_note but never names it.

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 only implied: an agent can infer this is the read counterpart to leave_a_note, but the description never says when to call it or when to prefer a sibling (e.g., read_in_the_library for written works). No exclusions or alternatives are stated.

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