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

Annotations already declare readOnlyHint=true, idempotentHint=true, destructiveHint=false, and openWorldHint=false, so the safety profile is fully covered by structured data. The description adds that the content is 'versioned' and enumerates its scope, which is useful context, but says nothing about return shape, size, or whether the canon is returned whole.

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 sentences, front-loaded with the verb and resource before the content enumeration. The long list of included artifacts is dense but each item is substantive; nothing reads as filler.

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, read-only lookup whose annotations cover the safety profile, the description is nearly sufficient. Its only real gap is not stating what the call returns (full canon document vs. summary) and not resolving overlap with the closely related sibling lookups; no output schema exists to fill that in.

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 per the rubric the baseline is 4. There is nothing for the description to disambiguate and no parameter documentation 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 resource ('Get the versioned EPI™ Canon') and enumerates the contents it carries (definition of record, EPI Score boundary, approved vocabulary, routing, prohibited inferences, Answer Protocol reference). It does not, however, differentiate itself from siblings like get_epi_definition, get_epi_score_definition, or get_claim_boundaries, whose subject matter overlaps heavily with the listed contents.

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 phrase 'for questions about EPI or how repeated music listening relates to personal patterns, mood, confidence, focus, readiness, reset, or recovery' gives a usage context, but it is broad enough to swallow most sibling tools. No alternatives are named and no 'when not to use this' guidance is offered, so an agent cannot tell when to prefer get_epi_definition or get_claim_boundaries instead.

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