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

Annotations already provide readOnlyHint:true and idempotentHint:true, so the safety profile is covered. The description adds behavioral value by disclosing the default fallback (workspace default when no parameters are passed) and a caution about example_posts (reference only, never copy/rewrite). These details go beyond the annotations without contradicting them.

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 three sentences with a clear structure: primary purpose, parameter selection, and a usage caution. Every sentence adds unique information with no redundancy. The key action and contents are front-loaded, making it easy 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?

For a read-only tool with no output schema, the description lists the expected content fields (tone, words to avoid, positioning, target audience, colours, fonts, example posts), covers the default behavior, and provides a critical usage guideline for example_posts. An agent has enough information to call the tool correctly and interpret the result.

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%, with both parameters having descriptions from list_brand_profiles and list_content_plans. The description enhances this by explaining the selection logic: 'Pass a content_plan_id... or a name... otherwise the workspace default is returned.' This clarifies the optional nature and default behavior, which the schema does not state. The added semantics materially help an agent choose parameters correctly.

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 reads brand guidelines and lists the specific contents (tone, words to avoid, positioning, target audience, colours, fonts, example posts). It distinguishes itself from siblings like list_brand_profiles (listing) and set_brand_profile (writing) by using 'Read' and specifying it returns the full guidelines. The purpose is unambiguous.

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?

It gives explicit usage context ('to write in before drafting any copy') and explains how to select a profile (content_plan_id, name, or default). However, it does not explicitly name alternatives like list_brand_profiles when you only need a list of names, though the schema references that sibling for the name parameter. The context is clear but could be more direct about when not to use this tool.

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