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

Annotations already carry readOnly, idempotent, openWorld and non-destructive, so the safety profile is covered. The description adds genuinely non-structured context: results are 'worked out for any year' (i.e., the big-day dates are computed, not static) and that each entry includes a map plus a qualitative description. No pagination or rate-limit detail, but little else is missing.

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 resource leads the sentence, which is good, but the long geographic roll-call (Tampa Bay through the Panhandle) and the sandbar-name list duplicate what the name parameter schema already shows. Roughly half the text is tourism-flavored enumeration that doesn't guide invocation.

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?

Six optional parameters with full schema coverage and rich annotations, and with no output schema the description usefully tells the agent what comes back (description, map, next big day). An agent could call this correctly from the definition as written; only the interplay between miles/limit and positional vs. name lookup is left implicit.

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 the schema already explains lat, lon, name, limit, miles and big_days. The description only restates the same examples ('Crab Island, Beer Can, Haulover') and the big_days flag; it adds nothing about how lat/lon interact, how limit and miles combine, or default behavior. 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?

Names a specific resource ('Florida sandbars and raft-up spots', 44 of them) and states the payload an agent gets back: character description, map, and the next big day there. The scope is unambiguous. It never names a sibling (find_places, artificial_reefs, shore_day) that an agent might otherwise reach for, so it stops 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?

'Give a position, a sandbar name, or big_days: true' enumerates the three invocation modes clearly, which is real routing guidance. There is no explicit when-not/alternative clause, so the agent still has to infer why it would pick this over find_places or artificial_reefs.

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