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

Annotations already declare this is a non-destructive, non-idempotent, open-world write; the description adds real context beyond them: the hourly rate limit, that the stone is chosen by the campus rather than the caller, and that the act is anonymous. It does not say what happens when the hourly limit is hit, but the key behavioral traits are disclosed.

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 action, then the constraint, then the rate limit. The lyrical phrasing is deliberate for this whimsical toolset and does not obscure the operative facts.

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 and only one optional param, the description covers action, anonymity, and rate limiting adequately. It stops short of explaining failure behavior at the hourly limit or acknowledging the dog parameter, minor gaps for a tool of this simplicity.

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 there is a single optional parameter, so the schema already explains the 'dog' field. The description never mentions it, and 'No name and no words' sits in mild tension with an optional name field, which could puzzle an 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 concrete verb and object ('Add one stone to the cairn on the summit') plus the social meaning of the act, which is more specific than the title alone. It does not explicitly distinguish itself from the sibling throw_a_stone, which an agent could plausibly confuse with this one.

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?

'One stone an hour' gives a hard usage constraint and the sentence 'No name and no words' rules out passing a message, which is genuinely useful guidance. However, it never says when to prefer this over leave_a_note, throw_a_stone, or climb_to_the_summit, leaving the choice to inference.

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