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

Annotations already cover safety (readOnlyHint, idempotentHint, destructiveHint=false) and open-world scope, so the bar is lower. The description adds genuinely useful behavioral context beyond them: it discloses the scoring inputs (solunar moon, NOAA tide swing, wind/pressure only for the first week) and a reliability caveat — 'Anglers' rules of thumb, never a promise' — which tells the agent how much to trust the output. No contradiction with annotations.

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?

The core purpose is front-loaded in the opening clause, which is good. But the rest is a single sprawling run-on sentence that crams in a full output inventory; the enumerated deliverables could be split or trimmed so each clause earns its place. Density without structure makes it harder to scan.

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 must explain what comes back, and it does so thoroughly — scores, best-bite hours, top 2 days with tide times, tide-direction-to-habitat mapping, and a spoken one-liner. For a zero-required-parameter, read-only forecast tool this is nearly complete; only input format details are thin.

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%, so lat, lon, and place are already documented, establishing the baseline of 3. The description's 'Give a position or a boat ramp name' confirms the either/or input pattern but adds no syntax, format, or default details beyond the schema. It neither compensates for nor erodes the schema's coverage.

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 states a concrete resource and action: a 1-10 Bite Score for today plus 14 days, best hours, best days, and a current Tide Read. That is far more specific than the title alone. It does not explicitly name a contrasting sibling (e.g., marine_forecast or live_conditions), so an agent must infer the boundary, which keeps it just short of a 5.

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?

Usage context is implied by 'When to go fishing in Florida waters' and the input instruction 'Give a position or a boat ramp name.' However, there is no explicit when-to-use-versus-alternatives guidance — nothing tells the agent to prefer marine_forecast for raw weather or live_conditions for current observations. Guidance is present but left largely to inference.

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