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

Annotations already establish readOnly/idempotent/non-destructive, so the safety profile is covered. The description adds real behavioral context beyond that: the board is scoped to the next main card, leverage is defined as win-chance share divided by ownership share, and the explicit caveat that underdog outcomes are DFS leverage rather than a betting edge steers how the result should be used.

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?

Front-loads the resource and scope before the field list, and the field enumeration is dense but earns its place for a tool with no output schema. The historical-stat sentence is verbose (3.2 wins per card, 95.5%, 93.8 vs 97.7 points) and the key 'not a betting edge' caveat is buried at the end rather than surfaced.

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?

With no output schema, the description fully compensates by enumerating every returned field, defining the derived leverage metric, and supplying base rates that let an agent interpret results. Scope (next main card), default site context, and the interpretive caveat round it out; nothing needed to call or explain the tool 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 description coverage is 100%, including enum explanations and defaults, so the schema already carries the parameter burden. The description adds conceptual meaning for two of them (leverage as a sortable metric, ownership varying by contest type) but no syntax or format detail beyond the schema, so baseline 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 resource and scope: 'Every underdog on the next UFC DraftKings main card,' then enumerates exactly which metrics come back (moneyline and movement, win/KO/sub/R1 chances, DK/FD points, salary, ownership, leverage). This is self-differentiating from siblings like invoke_mma_odds or invoke_mma_projections, which do not produce an underdog-only leverage board.

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 closing clause 'this is DFS leverage, not a betting edge' plus the leverage definition and historical base rates give clear context for when the output is appropriate. It stops short of naming alternatives (e.g., invoke_mma_odds for straight odds work) or stating exclusions, so it is clear context without explicit routing.

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