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

There are no annotations, so the description carries the full burden, but it only states what the tool returns and gives no behavioral traits such as whether it performs computation, fetches live data, has side effects, or how the heuristic is derived. The name implies read-only, but the description adds little beyond that.

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 front-loaded sentence with no filler. It is appropriately compact for a simple one-parameter getter, though the brevity comes at the cost of needed context.

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 low-complexity tool with one optional parameter and an output schema, the description is minimally viable: it identifies the resource and the symbol scope. However, it does not explain what the pin/magnet score means or when an agent should prefer this tool, so the context is incomplete for a non-domain-expert agent.

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?

The schema has one parameter, 'symbol', with 0% description coverage, but the description only repeats the word 'symbol' without explaining valid values, formatting, or the meaning of the default SPY. It does not compensate for the schema's lack of semantic detail.

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 the exact resource ('Pin score / magnet heuristic') and ties it to a symbol, so an agent can tell this tool is for retrieving a pin/magnet reading for a single ticker. It is specific enough to stand apart from the many get_* siblings, though the jargon is not explained in plain language.

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?

No guidance is given for when to use this tool versus alternatives, nor any exclusions or prerequisites. The only implied usage is 'when you need a pin score,' but the description does not place it in a broader decision context among the sibling tools.

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