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

Annotations already declare readOnly/idempotent/non-destructive/closed-world, so the safety profile is covered. The description adds genuinely non-derivable behavior: results split bodyweight vs weighted variations, empty results mean no catalog match, and the agent must not fabricate a demo. Pagination/`limit` behavior is the only gap.

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?

Five short, front-loaded sentences; each one carries a distinct instruction (search axes, query hygiene, variation handling, empty-result semantics, out-of-scope). No filler or restatement of the title.

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 5-param search tool with no output schema, the description covers intent, query discipline, result interpretation, and exclusions well. The two remaining blanks are the unmentioned `limit` parameter and the lack of an explicit handoff to the get_exercise sibling.

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 0%, so the description carries the burden, and it does name query, equipment, category, and muscle with useful framing (alias support like 'RDL', concise-name constraint, unspecified-equipment fallback). However `limit` is never mentioned and no format/syntax expectations are given for the free-text fields beyond brevity.

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 names a specific verb+resource ('Find exercise demonstrations') and enumerates the exact search axes: name/alias, equipment, category, muscle. It does not differentiate against the sibling get_exercise, so an agent has to infer that this is the broad search while the sibling is the single-item lookup.

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?

Strong contextual guidance: 'Pass a concise exercise name, not the whole user message,' the fallback behavior when equipment is unspecified, and an explicit exclusion ('Not for diagnosis or personalized injury rehabilitation'). It stops short of naming the alternative tool (get_exercise) for direct lookups, which is the one routing decision left to inference.

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