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

Beyond the readOnlyHint annotation, the description adds valuable behavioral context: it is a 'dashboard pointer, never empty,' meaning it always returns data without requiring read_token. It also conditions some metrics on 'where the server has them,' disclosing potential data gaps. This adds meaningful nuance beyond the annotation.

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?

The description is front-loaded with the key metrics in the first sentence, and the remaining sentences are compact. The phrasing 'No read credentials: a dashboard pointer, never empty' is terse but informative, and the pointer to `your_projects` is a useful aside without bloat.

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, the description lists the expected metrics (p50/p75/p95, worst, p99, spike ratio, stdev) and notes that some may be absent depending on server data, which gives the agent a good sense of the return shape. It does not fully specify the list structure or ordering, but the first sentence covers the essentials for a simple read-only tool.

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%, so the baseline is 3. The description adds minimal parameter-specific meaning; 'No read credentials' suggests read_token may be unnecessary, but it does not clarify when to use project vs install_id. This is adequate but not compensatory beyond 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?

The description clearly states the tool produces per-screen performance percentiles (p50/p75/p95), worst rating, p99, spike ratio, and stdev spread, which is a specific and unique resource among siblings. It does not explicitly differentiate itself from similar tools like boosthis_snapshot or boosthis_trend, but the metric list is distinctive enough to identify its purpose.

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?

The description implies usage for retrieving session summary metrics and notes that no read credentials are needed, but it does not explicitly say when to prefer this over alternatives. The reference to `your_projects` hints at an alternative for more projects but does not specify selection criteria, leaving the agent to infer the context.

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