add_to_block

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

With no annotations at all, the description carries the full burden, and it does disclose one non-obvious behavioral fact: the block is mutated into a superset, and prescriptions must be set separately. It says nothing about permissions/auth, duplicate-exercise handling, or whether the append is idempotent, which matter for a write operation with zero annotation coverage.

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 short sentences with the primary action front-loaded and the follow-up instruction second; nothing is padded. The trailing "turning it into a superset" phrasing is slightly ambiguous about whether that is automatic behavior or a semantic label, costing a point.

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?

An output schema exists, so return values need not be explained, but the tool is a 4-parameter mutation with no annotations and 0% schema coverage. The description leaves the identity/role of program_workout_id and team_id and the ordering constraints between block and workout entirely undocumented, which is not enough for an agent to call it confidently.

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% across 4 parameters, so the description must compensate and it largely does not. It hints that exercise_ids are library exercise identifiers and that block_id must be existing, but program_workout_id and the optional team_id are never mentioned, leaving their roles and required relationships unexplained.

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 ("Append library exercises to an existing block") plus the resulting state change ("turning it into a superset"). It does not distinguish itself from the sibling add_exercises, so an agent cannot tell from the description alone which of the two is the right append tool.

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?

Explicitly describes the required follow-up step: targets must be set afterward with set_prescription, naming the sibling to call. That is real workflow guidance. It stops short of a 5 because it never states when to prefer this over add_exercises or what preconditions (e.g. block must already exist in the given workout) apply.

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