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

Annotations already declare readOnly, idempotent, non-destructive and closed-world, so the safety profile is fully covered. The description's one genuine contribution is the cost disclosure ('Costs 10 credits'), which an agent cannot get from annotations or schema. It says nothing about result volume, pagination strategy, or how cost scales with seasons versus single games.

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?

A single dense sentence, front-loaded with 'Use for' and the data type, then the scopes, then the payload fields, then cost. No filler; every clause carries information. It is slightly compressed — it could split the cost note out for readability.

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 shape need not be explained, and annotations cover safety. The remaining gap is the undocumented identifier parameters and the absence of any guidance on the 10-credit cost versus result size (up to 2000 pitches per call), which an agent budgeting requests would want.

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 only 43%: game_id, batter_id, pitcher_id and offset have no schema descriptions at all. The description partially compensates by implying the three access modes (game / pitcher / batter), which is the key modeling decision for these undocumented IDs. It adds nothing about offset pagination, limit defaults, or how season interacts with game_id.

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 opening phrase 'Use for pitch-by-pitch data' names a specific resource and enumerates the three scopes it supports (single game, pitcher season, batter season) plus the fields returned (count, pitch type, velocity, location, result). That distinguishes it from coarser siblings such as get_plate_appearances, though it never names those siblings explicitly.

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?

'Use for pitch-by-pitch data' is an implied usage cue, and the enumerated scopes hint at when the tool applies. However, it gives no exclusions or routing guidance against the many adjacent siblings — get_plate_appearances, get_pitch_mix, get_spray_chart, get_game — which overlap heavily with this data.

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