Fireworks over the Yard

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

Annotations declare a non-destructive, non-read-only, non-idempotent action, and the description adds the crucial behavioral fact those annotations cannot convey: the effect is broadcast to every connected screen, so the blast radius is all sessions rather than the caller's. It also discloses the return value ('Says how many pages saw them'), which matters because there is no output schema. It stops short of saying what a repeat call does or whether the display can be interrupted.

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 and scope before the use case. Minor flaw: it switches terminology from 'screen' to 'pages' in the final sentence, leaving mild ambiguity about whether pages and screens are the same thing.

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 zero-parameter, no-output-schema side-effect tool, the definition covers what it does, where it lands, when to use it, and what comes back. Only idempotency/retry behavior and whether the effect is disruptive to the user are left implicit.

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?

The tool takes zero parameters, so the baseline is 4 and there is nothing for the description to clarify or compensate for. The description correctly implies no configuration is needed.

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 effect ('Launch fireworks over the Yard') plus an explicit broadcast scope ('on every screen connected to Agent Guild'). That scope makes it trivially distinguishable from the read/session-management siblings (guild_status, list_sessions, read_screen), which all operate on data rather than emitting a visual event.

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 a concrete positive trigger: celebrate something the person cares about, with examples (tests, a build, a release that passed). It does not state any when-not condition or note that this is a celebratory/novelty action rather than a routine one, but the intended context is clear enough for an agent to route to it correctly.

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