networking_mtu_size_calculator

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

Description adds value beyond annotations by detailing that it is pure offline math, contacts no host, and has a rate limit of 60 requests/minute. No contradiction with readOnlyHint and destructiveHint 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?

Description is a single paragraph of about 6 sentences, front-loaded with purpose. Every sentence adds value, though slightly denser than necessary; could be broken into bullet points for readability.

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?

Given rich schema with enums, full parameter descriptions, output schema present, and annotations, the description still adds critical context (rate limits, alternative tool, return fields) and is sufficient for an agent to select and invoke correctly.

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 has 100% description coverage, but the description adds useful context such as listing RFC byte sizes for encapsulations and stating that unknown encapsulation IDs are rejected. It explains the effect of each operation mode beyond schema enums.

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 clearly states the tool computes inner MTU, TCP MSS, usable payload, and overhead for encapsulations. It distinguishes three operations (compute, presets, pathMtuDiscovery) and explicitly contrasts with sibling tool networking_network_latency_calculator.

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?

Provides explicit guidance on when to use each operation and when to use an alternative tool ('use networking_network_latency_calculator to interpret ping or speedtest samples instead'). Also mentions read-only, non-destructive, and rate-limited behavior.

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