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

Annotations already declare readOnlyHint=true and destructiveHint=false. The description adds a useful behavioral cap ('most recent 30 points') and single-keyword scoping, but it does not disclose ordering, time intervals, or what each snapshot point contains. This is similar to the baseline where annotations cover safety but return behavior is thin.

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 description is a single focused sentence with no filler. It front-loads the resource and scope, then appends the limit 'most recent 30 points'. Every word adds value.

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?

For a simple read-only, one-parameter tool, the description is mostly complete: it states what is returned, for what input, and how many points. With no output schema, it could have described the shape of a snapshot point more explicitly, but this is a minor gap given the low complexity.

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 fully documents the only parameter. The description only restates 'one keyword phrase' and adds no additional semantic details like matching behavior or formatting, so the baseline score of 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?

The description names a clear resource ('rank/share snapshot history') with a specific scope ('one keyword phrase') and a quantifier ('most recent 30 points'). It is more specific than the tool name/title, though 'rank/share' is slightly ambiguous and no sibling is explicitly contrasted.

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 phrase 'for one keyword phrase' implies this is for single-keyword historical lookups, but the description does not mention related tools like get_keywords or get_keyword_market_performance, nor does it say when not to use this tool. Usage context is implied rather than explicit.

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