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

Annotations only say readOnlyHint=false, destructiveHint=false, openWorldHint=false. The description goes well beyond them by disclosing the non-obvious write side effect (the pick is recorded privately so the coach gets credit), the exact return scope (first week only, not the whole program), and two negative guarantees about pricing and purchasing. These are behaviors an agent could not infer from structured fields.

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 sentences, front-loaded with the triggering condition, then what is returned, then the constraints. No sentence is redundant and nothing is buried.

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 one-parameter read/get tool with a full output schema, the description covers trigger, return scope, side effect and boundaries. Nothing an agent needs to call it correctly is missing.

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% for the single program_id parameter, whose schema description already states where the id comes from. The description merely repeats that provenance in narrative form and adds no format, length, or validity detail, so the baseline of 3 applies.

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 (retrieve one Phorme program's details) and immediately scopes the payload: the program plus every session of its first week and a descriptive link. It is clearly distinguishable from the sibling search_phorme_programs because it names that tool as the source of the id.

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 an explicit trigger condition: 'when the user picked one program from search_phorme_programs and wants its details.' It also states the boundaries of what will happen ('never shows prices or starts a purchase'), so an agent knows this is not a purchase or pricing path.

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